1. The Postal Service, "Against All Odds" View this video on YouTube The Postal Service's "Against All Odds" is from a movie you never saw (apologies to those of you with prominently displayed "Wicker Park" shrines), but it's amazing. It strips down the bombast of Phil Collins' original and sounds like a raw nerve with a coating of that Postal Service electronic earnestness that made everyone love their one album, "Give Up." This song is so good that NPR's "This American Life" used it in a story to illustrate the power of Phil Collins' music, particularly after a break-up. It's easy to dismiss Phil Collins as overly sentimental, but the Postal Service version of this song reminds us why the original was so successful.Best line: "You're the only one who really knew me at all." 2. Iron & Wine, "Such Great Heights" View this video on YouTube Speaking of the Postal Service, Iron & Wine did a great cover of the Postal Service's biggest song, "Such Great Heights." The original has an innocence and driving energy behind it, but Iron & Wine slow it down and make it beautiful and heartbreaking but full of love. Just don't let your hipster hatred for "Garden State" or your anti-corporate feeling about that M&M's commercial take away from how much you love this.Best line: "I have to speculate that God himself did make us into corresponding shapes, like puzzle pieces from the clay." 3. Scala & Kolacny Brothers, "Creep" View this video on YouTube Quit thinking about that Facebook movie trailer that used this song and bask in and enjoy this choral rendition of Radiohead's modern rock classic. Piano and voices make the pain of this song that much more raw. And those whispers near the end? Shivers.Best line: "I wish I was special. But I'm a creep." 4. Nada Surf, "If You Leave" View this video on YouTube I admit that this song has a special place in my heart due to its excellent use on an episode of "The O.C.," "The Goodbye Girl." But don't let my love for teen television let you ignore the fact that this new wave tune, sung with just a little more heartbreak than the original, is the world's best song for when you know the person you love is leaving you and you'll do anything to make it not so. (And do yourself a favor and watch Seth Cohen saying goodbye to his friend and onetime love Anna on "The O.C.")Best line: "You always said we'd still be friends someday."Bonus best line from "The O.C.": "Confidence, Cohen." 5. Frente!, "Bizarre Love Triangle" View this video on YouTube The song, originally by New Order, has a title that adds a layer of intrigue that's never fully explored in the body of the song itself. But Frente took the song away from the '80s new wave of synthesizers and drum machines and gives it to you with just one woman's voice and a guitar being plucked.Best line: "Every time I think of you, I get a shot right through into a bolt of blue." 6. Jeff Buckley, "Hallelujah" View this video on YouTube Sure, this song is the most covered and the most overused in every single piece of pop culture ever, but that doesn't mean it isn't still amazing. It's also the version that woke everyone up to how beautiful the song is for those who couldn't get past Leonard Cohen's gravelly voice in the original, and it features lyrics that Cohen had only been delivering live. Cohen also offered a more cynical take, while Buckley stands up and says, no, this really means something, shut up and listen. It's a song that's biblical and about love and lust and everything. And if it's good enough for the season finale of the best year of "The O.C.," it's good enough for me.Best line: "Maybe there's a God above, but all I've ever learned from love was how to shoot somebody who outdrew you." 7. Amy Winehouse, "Valerie" View this video on YouTube The music Amy Winehouse turned out in her short, tragic life often had a retro vibe, but while "Valerie" may sound like a Motown cover, it's actually a 2006 U.K. hit by the band the Zutons. But Amy helped make it a sensation around the world. She also doesn't try doing any gender swapping of the lyrics, originally from a male perspective, and adds a bit of intrigue. The lyrics also seem to have a bit of a personal connection, with talk of a love going to jail — which Winehouse's husband did — and the singer's body being a mess since their lover left.Best line: "I think of all the things, what you're doing, and in my head I paint a picture." 8. Jem, "Maybe I'm Amazed" View this video on YouTube One more song whose cover got more attention after being featured on "The O.C." Paul McCartney, after leaving the Beatles, was in the much reviled Wings, which was actually a pretty great band but was never, ever going to be the Beatles. Their live version of this song became a hit several years after McCartney's solo version, a song dedicated to McCartney's wife Linda, who he credited with helping him get through the Beatles' break-up. It's a powerful sentiment, one which Bruno Mars has recently been echoing by telling women they're amazing in "Just the Way You Are." I'm including the version from "The O.C." up above, offered as a wedding song in a scene filled with love and heartbreak.Best line: "Maybe I'm a lonely girl, who's in the middle of something that she doesn't really understand." 9. Johnny Cash, "Hurt" View this video on YouTube Most of us didn't know the Nine Inch Nails song "Hurt," but Johnny Cash covered it in the twilight of his years and hit everyone right in the chest with it. And its lyrics become even more powerful with Cash's years behind it, with talk about losing friends sounding like the ever-growing loneliness that comes with age, amplified by his death which came soon after. This is a song so powerful that Nine Inch Nails singer Trent Reznor acknowledged that this wasn't even his song anymore but Cash's.Best line: "Everyone I know goes away in the end." 10. Cat Power, "Sea of Love" View this video on YouTube It would be easy for "Sea of Love" to feel lost in time with an original version that includes a backup dudes going "bum, bum-bum-bum-bummm" and a very traditional structure from one-hit wonder Phil Phillips (no relation to American Idol winner Phillip Phillips), but like so many amazing cover songs, Cat Power minimizes the backing, letting the sweet song about love and memory stand out. (This band also bears no relation to BuzzFeed's Cat Power rankings.)Best line: "I want to tell you how much I love you." 11. Pearl Jam, "Last Kiss" View this video on YouTube Story songs are a little rarer than they used to be, at least outside of country music, but Pearl Jam brought back this tale from the early '60s of a young man who gets in a car accident that kills his beloved. Eddie Vedder's voice makes the song so much more pleading than earlier versions. Despite the song's dark subject matter, the chorus still contains hope, but that desperation in Vedder's voice makes it sound like it's a hope he doesn't quite believe in.Best line: "She's gone to Heaven so I've got to be good, so I can see my baby when I leave this world." 12. Michael Jackson, "Smile" View this video on YouTube The largest distance between cover and original in this list, silent film legend Charlie Chaplin composed the music or the 1936 film "Modern Times," though the lyrics were added later. Michael Jackson recorded it in 1995, and while it was originally scheduled to be a single, those plans were canceled. That doesn't take away from the power of this song almost a century after its birth, and one of the greatest vocalists of all time putting his spin on it just makes it feel that much more timeless.Best line: "Smile, though your heart is aching. Smile, even though it's breaking." 13. The Bird and the Bee, "Rich Girl" View this video on YouTube The Bird and the Bee put out an album that sounds absolutely insane: "Interpreting the Masters, Vol. 1: A Tribute to Daryl Hall & John Oates." But if you aren't that familiar with Hall & Oates and you actually listen to the thing, you realize that, without the '80s production making you so judgy, these songs are amazing. "Rich Girl" tells a story of privilege, and even includes some surprisingly naughty language for a mainstream '80s song.Best line: "Don't you know that it's wrong to take what is given you?" 14. Joe Cocker, "With A Little Help From My Friends" View this video on YouTube Just a year after its original release, Joe Cocker took this Beatles song to the top of the charts, and then, a year after that, performed it at Woodstock. He slowed it down and made it even more of a rock song — which makes sense with the legendary Jimmy Page on guitar. It's odd to say that you needed another song to make you realize how amazing a song by the Beatles was, but Cocker's version with his legendary rough voice is like some cold water in the face, grabbing you by the shirt instead of the mellow feel of the Beatles version. It also went on to remind another generation of how great this tune was when it was used as the theme on '80s TV period piece "The Wonder Years."Best line: "What do I do when my love is away? Does it worry you to be alone?" 15. Kelly Clarkson, "Respect" View this video on YouTube "American Idol" has made a lot of stars, but those who know the show will never forget the original Idol, Kelly Clarkson. "Respect" by Aretha Franklin is a masterpiece, but Kelly showed that she was worthy of a second look and took her dark horse position to win the first season of that show. Her version of "Respect" is one of the pieces of the puzzle that let her come to the front, and reminded a new generation to give Aretha and this song their respect.Best line: "All I'm asking is for a little respect when you get home. Just a little bit." 16. Gary Jules, "Mad World" View this video on YouTube The song, originally released in 1983 by Tears For Fears, still has the same lyrics, but Gary Jules slowed it down and toned down the production to point out the true tragedy of the song's message. It was recorded by Gary Jules for the movie "Donnie Darko," now a cult classic. It's a reminder that you're not the only one who thinks things seem a little crazy — you're not alone.Best line: "The dreams in which I'm dying are the best I've ever had." 17. Mary Beth Maziarz, "Daydream Believer" View this video on YouTube This was the first cover song that ever made me wake up to how good the original was (no pun intended). I heard it in the show "Dawson's Creek," and the original is by the Monkees. The Monkees, who were a band created for a TV show trying to capitalize on the fame of the Beatles. But guess what? It's beautiful and hopeful and special. (Check out "Dawson's Creek" clips set to this song to experience a little of what I get sentimental over.)Best line: "Cheer up, Sleepy Jean." 18. The Fugees, "Killing Me Softly" View this video on YouTube Roberta Flack's original is wonderful, but the arrangement is somewhat traditional. The Fugees brought a hip-hop influence to their version, but also remained largely true to the original and let Lauryn Hill sing the hell out of it. They exposed the song to a whole new audience while only really changing the outer trappings of the song and adding a beat. The Fugees also later performed the song with Flack at the MTV Movie Awards.Best line: "I felt he found my letters and read each one out loud." 19. PS22 Chorus, "Just Dance" View this video on YouTube The PS22 Chorus is pretty simple — they're a public school choir. However, they take what you'd expect from a school chorus and turn it, delivering sweet, honest takes on popular music. Their most popular is Lady Gaga's "Just Dance," with over 5.6 million views on YouTube. They take the song out of the club and let it just be a song without all the trappings and associations that Lady Gaga carries.Best line: "Just dance. Gonna be OK." 20. Pomplamoose, "Telephone" View this video on YouTube The second Lady Gaga song on this list, Pomplamoose takes another club song and makes it less about the club and more about the song's clever production, particularly with their video, which offers a transparent look into how the song's sounds were put together. (And they've got some pretty sweet dance moves.) The original is fun, but Pomplamoose elevates it from a song to dance to into a song to experience.Best line: "You should've made some plans with me, you knew that I was free." 21. Glee cast, "Don't Stop Believin'" View this video on YouTube It's the song that made Fox's "Glee" a phenomenon. In what may be rare on this list, it may actually be more earnest and bombastic than the original Journey song — which, when it comes to an '80s band, is hard to do — but the cast's youthful exuberance, led by the late Corey Monteith, makes it possible to buy into it and come along for the ride. Unlike the original's use to end "The Sopranos," this song began something, and when you listen to it, you feel like you can begin something too.Best line: "Don't stop believin' — hold on to that feeling."