Fruits Basket
Gravitation
Code Geass
Death Note
Ouran High Host Club

Fruits Basket
Ouran High School Host Club

inuyasha, kaleido star.. ah.. too many.. hehe..

I haven't watched many more than once, I think the only ones are Ghost in the Shell and Cowboy Bebop.

Gravitation :)
(Its Yaoi.. but its so adorable.)

Cowboy Bebop, Eureka 7, Chobits, some seasons (sagas?) of Dragonball Z

bleach! and blood+...

Beck is the only anime so far that I rewatched a couple of times.

Samurai Champloo
Fruits Basket
Gundam.....almost all of them lolololol
Boys over Flowers

Claymore
Fruits Basket
Sailor Moon
Dragon Ball
DBZ
anything made by *Hayao Miyazaki*
Hellsing
DearS
Chobits
Cowboy Bebop
Millennium Actress
Ouran High School Host Club
...and some others I'm forgetting...
OHSHC is my fav, tho! XD

edit: just realized...My list is one of the longest... I'm such an ex-otaku... ;_;