In the series ".hack", what was first - the PS2 game, manga, or anime? Where do I start?

Question

I am interested in the .hack series, but I don't know where I am supposed to start. I read a manga of it at a bookstore, but it seemed to come after the original story line. I'm guessing that it begins in the PS2 games, but am not sure if those are also based off of something.

Answer 1

.hack// sign started it all
.hack//liminality is the anime about what happens on the real world while the events on the ps2 game unfold
.hack// manga is about the second series.

Answer 2

start at manga book stores my friend thats the right one