I can think of two games that really stick out as being ones I enjoyed despite reviews:
Breakdown and
Monster Hunter
Breakdown was a game that interested me ever since the original E3 trailer was shown. It had a fairly interesting concept (first person hand to hand fighting game), and the presentation looked very nice. Upon playing it, three things impressed me most: the immersion ("seeing the game through the eyes fo your character" is a phrase almost exclusive to Breakdown), the story, and the combat system. While ranged combat was pretty weak, thanks in part to the rather simplistic aiming system, the hand to hand combat was extremely fun once you got into it. The controls are quite tight, you aren't nearly as "floaty" in this game as most first person games are, partially because your movements are dictated by full body awareness. The story really surprised me though, it has by far the best story (and plot twist) of any first person action game. Of course, that isn't saying much since most first person action games have terrible stories, but even on it's own it's a very well-presented plot.
Breakdown did have it's flaws, especially when fighting against multiple enemies and the generic/repetitive nature of some of the environments (although they do come up with a good reason for needing to retrack your steps). Overall though, I thought it's execution was very well done, and it's sad to think that they'll never be able to make the sequel which they seemed to plan for because of the game's poor sales. It has one of the few cliffhanger endings that doesn't make me feel cheated.
Monster Hunter is sort of a love-it-or-hate-it game. The concept is something almost anyone can enjoy (killing big monsters), but it's not a game that's easy to pick up and play. The combat system takes some getting used to, you have to plan and time your swings (or jabs, or shots), or you'll quickly be run over by a rampaging dragon. It certainly has a Diablo-level repetativeness to it, especially since the areas themselves are pretty small. But, it does have a surprising amount of variety when it comes to enemies and environments, and playing online with 3 other people to take down a colossal monster is really enjoyable. Again, the game did have it's flaws, and I can see why many people would hate it, but if you can manage to get into it, there's actually a pretty involving game to be found.
Jam it back in, in the dark.