Limegreen

Definitely Ar Tonelico. I played it via pcsx2.

Is that bad? I thought to watch it once but never had the chance o.o

Actually, my friends are like "What? Why? It's good". But for me I couldn't handle it.

You should try watching it.

Hoshizora no Memoria -Wishing Upon A Shooting Star-

I don't have a particular anime that I regret watching but if I have to choose.. it would be Maria†Holic.