I've actually only watched the first half of the first series, and in Japanese. My g/f is an anime Nut, so she had it. After starting to get into MMORPGs again, I realized waht .Hack was about so I started watching it.
The premise is intriguing, following the live of peoples Characters in a game...
The music and the scenery is waht really blew me away.. the whole show just has this overwhelming surreality to it.
My choice for avatar was either Tsukasa or the cat Maha.