Stalker: Clear Sky, it never crahed for me (with patches) and the only time something weird happened was when I showed up to the Freedom base to find a couple of dead guys, no huge problem as they were carrying some fancy guns. Although the end was a bit shit.

Crusaders of Might and Magic - Terrible reviews all around, game's long since forgotten. But I had a blast playing it; I rarely play through games 'till the end but I did with this one. It combines action with RPG in a nice way. Has interesting action determined by timing (when to block, attack left, right, power attack etc), abilities and items. Has side quests, stores, inventory, leveling and other interesting bits like RPGs have.
Lemmings Revolution - For some reason, this game got some bad reviews as well. Regardless it was a lot of fun. The game simply was Lemmings but with small twists, such as levers, bridges, doors, different water passable by different lemmings, anti-grav and so on. Still has the basic Lemmings skill set-climber, floater, bomber, blocker, builder, pickaxe, digger, and basher.
I can't think of any modern games, simply because I don't read reviews anymore. With easy access to demos and videos, it's easy to judge if you'll enjoy a purchase yourself.

It wasn't awful, it didn't deserve it. The minimun it should have got was a 6/10, and that's being harsh. I actually played through the game twice, since I enjoyed it the first time.

The Elder Scrolls III: Morrowind. I was told by quite a few sites that it was a sucky or mediocre game. I must have sunk at least 100 hours into it, mostly just wandering about the world.
Also, Batman Begins for the GCN. Really enjoyed it, despite the fact that I didn't like the movie and the game got pretty harsh reviews.

I loved Trespasser, despite all of the terrible reviews. I spent so much time just playing around with the game world / physics.

I did think of a couple of others, although they probably rank more as guilty pleasures than something I loved:
Total Overdose: A Mexican-themed GTA III clone. Totally dumb, ridiculous, and over-the-top, but it made me laugh a lot. In a good way.
Hard Truck: Apocalypse: It's an open-world RPG where you basically play a truck. I found it strangely engrossing; probably something to with it being developed in Russia, where most of the games have a certain daffy charm.
UberSoldier: The reviews were bad and the voice-acting was even worse, but as a straight-ahead arcade FPS, this was well done.

For me it was 007: Nighfire. It received some rather less than average reviews but I thought that the game was great.
also,
Star Wars: Battle for Naboo. a game rated certainly on the bad side of average but one I thought was just fun.
Both games I've played through from begining to end (+ some bonus stages) and I really enjoyed them both.

Fable.
I didn't immerse myself in Peter Molineaux's stupid hype before the game came out,

Kingdom Hearts II. It's pretty suprising I played at all, considering that I didn't like the original. Whenever I talked to someone about it, the instant response was "How to win: Press X until credits roll." There's definitely some truth to that statement, but for me it was still really enjoyable.

I don't think that game got a single bad review, I don't think that should count :)

Hands down Psychonauts. I saw this game in the store and my gut told me this was a bunch of popcap style games. it wasn't until i read reviews and saw videos when i realized how wrong i was. and then when i actually bought it and played i was enamored! :)

Anyone who hated MGS2 most likely did so because of:
UGH CUTSCENES or
UGH RAIDEN
Both were great. There will be no discussion.I genuinely liked the arm mechanic. It was horrible and unweildly, terrible to aim with, got caught on things, but damned if I didn't think it was cool.
And the story, oh man the story.

I liked Delta Force 1 and 2. Terrible AI, textures, models... but damn sniping someone from 80 miles never got old no matter how unrealistic.

that is villainous, my friend.
i remember playing the demo for that when it was released. glass broke very nicely. that's the only good thing i can remember about it.