I saw both Air and Kanon, also watching CLANNAD. Kanon is my personnal favorite, as its very sad thru out the series. Clannad also looks like its gonna be awesome (only 3 episodes out)
I have a sorta love-hate thing with Higurashi, I hate that the story keeps changing, but i want to see what happens in each arch.
Shakugan no Shana FTW (if you like to see lolis kick ass and take names)
I want to watch #3, as seeing 1 guy on an all-girls island seems awesome.
Green Green. its alright romance one.
Futakoi. Its a really nice one.
Thats the only 2 i can remember, i know more of those type of ones, but some are old...