1. Chris Pratt as Summer's hippie friend at Brown: Warner Bros. / Via ecleader.org His name was Che Cook and he loved hemp. 2. Paul Wesely as Donnie Warner Bros. / Via fanpop.com He worked with Ryan at the Crab Shack and then pulled a GUN on Luke at a party. Also he was one of many future vampires to appear on the show. 3. Paris Hilton as a random club girl named Kate: icouldnthelpbutwonderblog.blogspot.com Yes that is Paris taking a selfy with a flip phone. 4. Colin Hanks as Grady Bridges: Warner Bros. / Via complex.com He was the star of a fictional soap opera called "The Valley" and he had #COOLHAIR. 5. Amber Heard as this salesgirl: Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com The season was two and Amber was brilliant in her role as salesgirl with an attitude. 6. Morena Baccarin as Maya Griffin: Warner Bros. THE MOM FROM HOMELAND. THE MOM FROM HOMELAND. 7. Emmanuelle Chriqui as Jodie Warner Bros. / Via emmanuelle-chriqui.com Her character was mostly insignificant except for causing Marisa to make this face. 8. Jeffrey Dean Morgan as this prison guy: Warner Bros. / Via Flickr: jdmschool Fun fact: Jeffrey Dean Morgan is now married and has a child with Hilarie Burton, from One Tree Hill. 9. Jamie King as this spring break girl: Warner Bros. / Via fanforum.com She was lucky enough to have Seth Cohen lick whipped cream off her body during a spring break television competition. 10. Shailene Woodley as Marissa's little sister Warner Bros. / Via entertainednews.com Shailene was little Katilin Cooper until they sent her away and she was replaced by that older girl. 11. Jackson Rathbone as Kaitlin's college ex-boyfriend: youtube.com See, another future vampire. 12. Ashley Benson as an enemy of Kaitlin's: Warner Bros. / Via prettylittleliars.alloyentertainment.com Also this is one of three girls from Pretty Little Liars to appear on the show. 13. Janel Parrish as this teen: prettylittleliars.alloyentertainment.com This is the second. 14. Lucy Hale as Hadley, a friend of Kaitlin's: Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com ANDDDDDD, this is the third. 15. Chris Carmack as Luke: Warner Bros. / Via listal.com Guys, he's on Nashville now. 16. Nikki Reed as Sadie: Warner Bros. / Via tvmedia.ign.com ANOTHER VAMPIRE. 17. Logan Marshall Green as Trey: Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com Trey was actually a big character and was the most important person in one of the most memorable scenes in television history, I'm just here to remind you that this is the guy who looks like Tom Hardy, but isn't Tom Hardy. 18. Steve-O as a Marine: Warner Bros. / Via tasteofglory.wordpress.com He was probably already Jackass famous, but still deserves this mention. 19. Chris Brown as a band geek named Will: Warner Bros. This is when the world was a better place. 20. Cam Gigandet as Volchok: Warner Bros. / Via fanpop.com ANOTHER VAMPIRE AND ALSO THE JERK WHO BASICALLY KILLED MARISA. (spoiler alert). 21. Olivia Wilde as Marissa's girlfriend: Warner Bros. / Via khaokal.netslums.com Look at Olivia Wilde. This is actually Olivia Wilde. 22. AnnaLynne McCord as this girl who just wants to get high: fanpop.com Hey, who can blame her. 23. And Max Greenfield as young Sandy Cohen: Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF Tap to play or pause GIF youtube.com Needs more eyebrows, but otherwise: APPROVED.