I don't think it's that weird, as others may have alluded to, this generation hasn't had many "OMG U HAVE 2 PLAY THIS" titles. Since you like doing crazy challenges you set for yourself and mentioned MGS i might recommend MGS4 since there's a million different weapons and equipment and a million different ways to tackle each area. Could be fun.

Personally I like a lot of the online games that have come out on consoles, but they're not necessarily more fun than anything you could get on steam for cheap.