Oh lawd. Your poll....
Anyways, I've compiled a list before for similar topics. I'll just go ahead and copy/pasta. This includes complete IPs (all seasons/movies/etc. pushed into one listing). I'm also ignoring the new season that's currently airing.
1. Code Geass
2. Kara no Kyoukai - the garden of sinners
3. Nodame Cantabile
4. Cowboy Bebop
5. Great Teacher Onizuka
6. Steins;Gate
7. Outlaw Star
8. Trigun
9. Spice and Wolf
10. K-ON!
11. Sayonara Zetsubou Sensei
12. Trapeze
13. Howl's Moving Castle
14. Arakawa Under the Bridge
15. Tatami Galaxy
16. Gundam Wing
17. Fullmetal Alchemist
18. Gurren Lagaan
19. Gunbuster
20. Ouran High School Host Club
Right Outside:
Highschool of the Dead, Toradora, Amagami SS, Claymore, and Senkou no Night Raid