Evangelion was the first anime i ever watched that gave birth to this anime fan
after this awesome anime i have to quote twice CLANNAD + CLANNAD AFTER STORY all being shouted as it has a really, really, really awesome plot and is very well-made and Code Geass.
these 3 are TOP 1 in my list.
Toradora, Heroic Age, School Days, Hell Girl and Death Note are TOP 2 in my list.
and my TOP 3 goes to:
Fullmetal Alchemist Brotherhood (way better then first version the history from the manga view wow...)
Da Capo Series
Claymore
To Aru Kagaku no Railgun and To Aru Majutsu no Index
Koukaku no Regios...
Guess that is my Fav List TOP 3....
by the way sorry to break you down but Avatar is not an ANIME it is an animation... :P