The first .hack that I experienced was .hack//Sign on the Adult Swim; but I first heard of the .hack premise in (here it comes) EGM and GMR (Game magazines). .Hack was the first MMORPG that wasn't really an MMORPG, and the editors loved to make game-within-a-game jokes.
Recently, a friend of mine lended me a copy of her .hack G.U. game (First enry in the G.U series, btw.). Initially, I felt confused. "Who the heck is the 'Shino' girl that Haseo keeps mentioning?!" I later found out that there was an anime series that expanded on that story. I've yet to see said series.
