Essentially, what was the crappiest game you ever played that you just couldn't seem to stop playing?
Mine's the .Hack//G.U. series (since all three are essentially the same game, more like overly expensive expansion packs than sequels). The story OOZES cheese, the battle system is lackluster, magic is awful, alchemy and item cutomization are bland and same-y, and the item system is one of the worst I've ever seen. But I love it. I love this series. And I DON'T. KNOW. WHY. Maybe it's because the story tries so very, very hard to seem threatening despite its premise (since when were nuclear reactors connected to the internet??) and it makes me laugh; maybe it's that the characters are lovable (Silabus, Gaspard, Atoli <333); or maybe I just wanted a JRPG bad enough at the time.
SO! Your turn, general public!