Spoilers (obviously)...
1. Finn's Stormtrooper ID number is FN-2187, which is the same number as the cell block where Leia is imprisoned in A New Hope.
2. Many familiar banners can be seen hanging outside Maz Kanata's outpost, including several of the podracers' flags from Star Wars: The Phantom Menace and the mythosaur skull from Boba Fett's uniform.
3. Podracers can also be seen in the background of several of the scenes that take place on Jakku.
4. The Starkiller base got its name from Luke Starkiller, which was what George Lucas originally named Luke Skywalker in early drafts of Star Wars.
5. Rey's outfit is probably inspired by early drawings fom Star Wars concept artist Ralph McQuarrie for Luke Skywalker at a point when Lucas and McQuarrie were playing with the idea of making Luke a woman.
6. And that's not where the McQuarrie/Force Awakens connection ends. The snowtroopers in The Force Awakens wear outfits similar to McQuarrie's concept art for Hoth, right down to the insignia.
7. And the archway in Rey's village on Jakku was originally designed by McQuarrie to be part of Jabba's Palace on Tatooine.
8. BB-8's design also may have been inspired by Ralph McQuarrie's concept art for R2-D2.
9. The Millennium Falcon has a rectangular antenna in The Force Awakens. That's because it lost its original antenna in the Battle of Endor.
10. Rey continues the rich tradition of disparaging the Millennium Falcon when she calls it "garbage."
11. Han and Rey also make references to Han's infamous line about the Millennium Falcon making the Kessel Run in 12 parsecs.
12. When Rey touches Luke's lightsaber and starts to have visions, some of the voices she hears will be familiar to a careful listener.
13. The wooden chest Maz Kanata keeps Luke's lightsaber in may be the same chest that Obi Wan Kenobi retrieves the same lightsaber from in A New Hope before he hands it over to Luke.
14. Ben Solo aka Kylo Ren, is probably named after Obi Wan Kenobi, who is referred to as Old Ben Kenobi in A New Hope.
15. During his battle with Rey, Kylo Ren receives a face scar to match his idol, Anakin Skywalker.
16. There is strong evidence to suggest that Snoke is actually Darth Plagueis.
Darth Plagueis is the Sith Lord referred to by Palpatine in Revenge of the Sith, who "learned to conquer death" and then was "killed" by his pupil, Palpatine himself. Among the evidence compiled by fans, Snoke is missing his lower jaw, which is similar to an injury Darth Plagueis received while training Palpatine, and there are striking similarities between Snoke's theme music and the music that plays when Palpatine tells the story of Darth Pagueis in Episode III.
17. The Millennium Falcon chess game that Finn accidentally triggers picks up right where the chess game between R2 and Chewie left off in A New Hope.
18. Finn can also briefly be seen taking the remote training droid Luke used in A New Hope out of a bag aboard the Millennium Falcon and inspecting it.
19. The woman rocking the Princess Leia buns in the Resistance headquarters is none other than Carrie Fisher's daughter, Billie Lourd.
20. The stormtrooper guarding Rey's cell who succumbed to her Jedi mind trick was actually played by Daniel Craig.
21. Radiohead's producer, Nigel Godrich, also makes a cameo as stormtrooper FN-9330, and composer Michael Giacchino, who has composed music for many of J.J. Abram's projects, plays stormtrooper FN-3181.
22. Lando's co-pilot, Nien Nunb, makes an appearance in The Force Awakens as a Resistance fighter along with the puppeteer who originally controlled the character, Mike Quinn.
23. Admiral Ackbar also returns, along with the actor that portrays him, Tim Rose.
24. A pink R2 unit called R2-KT makes an appearance in The Force Awakens.
25. Han delivers the iconic line "I've got a bad feeling about this" in The Force Awakens. The line has appeared in every Star Wars film.
26. Chewbacca's first meeting with BB-8 mirrors his interaction with the mouse droid in A New Hope.
27. According to the Star Wars: The Force Awakens Visual Dictionary, the helmet Rey wears belonged to an X-wing pilot named Captain Dosmit Ræh, who flew for the Tierfon Yellow Aces.
28. It also appears that Rey has had other run-ins with the New Republic, since she crafted a small Alliance pilot doll that can be seen in her quarters on Jakku.
29. The Abednedo X-wing pilot is named Ello Asty after the 1998 Beastie Boy album, Hello Nasty.
On the package of his officially licenced toy, the Aurebesh text on his helmet reads "born to ill."
30. At one point, Rey warns BB-8 to "stay off Kelvin Ridge." Kelvin was the name of director J.J. Abrams' grandfather, and he makes it a point to sneak a Kelvin reference into most of his work.
