I haven't player GTA4, so I can't comment on that.
DMC truly was IMO a 'bad sequel', I disliked most things about the game.
MGS 2 was a disapointing game, but not a bad game by any means. Though I can truly understand people's fustration at the whole Raiden situation.
I also think the likes of Super Mario Sunshine, Zelda II and Bioshock 2 all fall into the MGS 2 catagory as they were still very good games, just disapointing compared to their predecessor/s








