Lists, huh? Guess I'll do a Top 10:
1. Mobile Suit Gundam - A lot of nostalgia here, but I love a realistic war tale, and this is one of the best I've seen in anime.
2. One Piece - One of the most engaging "epic" adventures I've ever encountered. I love almost every aspect of it.
3. Sgt. Frog - One of the few comedy anime I could really get into, and once it grabbed onto my brain, it wouldn't let go.
4. Fullmetal Alchemist: Brotherhood - what do I need to say that hasn't been said a million times before?
5. Gurren Lagann - One of the most intense and thrilling super robot anime out there.
6. Dougram - Same with Gundam, only without the nostlgia.
7. GaoGaiGar + Final - I cannot separate the two. Easily the most refined pure Super Robot anime out there.
8. Gundam UC - Still has more one episode left to go, but I'm already sold. This is the loveletter to old mecha I've always wanted!
9. After War Gundam X - I love mechs. I love post-apocalyptic settings. I love it even more when you mix the two.
10. FLCL - That music! The rest was really fun and interesting, too. But still...THAT MUSIC!!!
Honorable mentions: Hunter X Hunter, Yamato 2199, Votoms, Legend of the Galactic Heroes, Berserk - once I finish all of these, I might have to redo my list...