I see you've already been recommended Clannad, if so do not forget the second season.

I've currently started returning to my basics as the recent seasons weren't taht good apart from 1/2 titles per season.
Right now it's Angelic Layer time, was Tenchi Muyo GXO before that. Angelic Layer should fit your tastes.

From this season I'd say Hyouka and Acchi Kocchi may be for you, otherwise Jormungand is the best currnetly running one.

ONE PIECE , just this , the perfection <3

Fairy Tail!!!! a really good anime IMO

Okay, yeah, forgot to mention that YOU might like Elfen Lied but not your girlfriend. It's not ohgodamazing, but it's pretty cool.

You have got to watch GANTZ!

Make sure you watch the uncut version! ;)

Hunter X Hunter

Boku No Pico, must see!

i can recomend - Inukami!, Death Note, Moetan ^_^

full metal alchemist !!!

Clannad? Then go with Kanan, another one of those really good works (in my opinion) by Kyoto animation. Also, Air if you have the time xD

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I hope it helps.

Might want to try:
Miracle Train... I'll try to post more if I can think of more xD

Chaos;head
Steins;gate
Code Geass (if you don't see this, you deserve to DIE)
Evangelion (actually you should have seen this)
Shonnen Bat (preatty fucked up)
Excel Saga (fun as hell)
Eden of the East (2 series + 2 movies, just Fucking EPIC)

Mirai Nikki and Death Note :)

Mirai Nikki of course

Skip beat, The world god only knows, shaman king