Games you weren't expecting to love, but did.

I've been up since 4am and my brain clearly isn't going to be working today :\.

Portal. Bucket loads of hype, annoying endless quotes, based on halflife 2... all big negatives but the game actually ended up being pretty damned good

Shenmue - Didnt expect to enjoy controlling a man's life so much! Now give me the rest of the story dammit!
ArmA II - Didn't enjoy the first much, had too much fun shouting down the mic with this one.
Audiosurf - Thought it would be a crap game that had no sense of rhythm, yet i was wrong...

Drakensang - I got it on a whim with no expectations at all, as I never heard of it before. It turned out to be a pretty solid game with good story.
Dark Messiah - I bought it only because of 'M&M' in the title, even though I was still angry at Ubisoft for making games not related to the old universe. An hour or two and I found DM a very good game (and very creative in terms of dealing with enemies)
Return to Krondor - it has terrible animations, repetitive fights but also a full-blown story and great deal of quests with surprising twists.

Resident Evil 5 and Call of Duty: Modern Warfare 2.

SSX Tricky- This was before I had played any extreme sports videogames like Tony Hawk . The whole idea of a snowboarding game sounded incredibly boring. When I heard of the game, I imagined it would be striving for a realistic feel, which is what put me off from ever trying the game. Then I played the demo in a playstation magazine, and it was over the top awesome fun so I bought the full game right away.
Elite Beat Agents- again just the whole concept seemed boring. I had seen videos of it in action, and I thought it looked stupid and unfun to play. I bought it anyway becauuse people wouldn't stop talking about how good it was. I decided to give it a shot and it was more awesome fun.
more recently is Tales of Vesperia. I had played Tales of Symphonia, and I HATED that game just for the story and voice-acting. If I really enjoyed the combat, I probably would have kept playing it anyway, but I thought the combat was just OK so I quit playing it after a few hours. I bought Tales of Vesperia because it was on sale for $10 at amazon, so I decided to give the Tales series another shot. I've only played it a little bit, so it's still too early to say I LOVE it,. I've been too busy playing my other holiday games. So far though I have found everything to be enjoyable and there is nothing I dislike it about it. I guess calling it a pleasant surprise is more accurate than saying I love it.
I also like how this thread is trying to be positive instead of being negative.:)
I find"most disappointing /overratedwhatever" type threads to be extremely depressing/aggravating to read, and I hate a lot of people for being a bunch of super gloomy joyless partypoopers

First of all, cover system in DoW was just a little 'extra'
Now, warcraft 3 clone? Hardly. W3 and DoW play very differently. W3 is essentially RTS and RPG hybrid, where your main goal from the first minute is to level up hero. DoW? Your first goal from the first minute is to fight the enemy. And once there's a first shot, fighting never ends, front is pushed forward and backward according to tactics both players choose. DoW IS an action strategy, an by preventing turtling it's pretty damn good at it - and yet, it keeps some kind of tactical depth, be it weapons you give to your troops, or how you use them later. I could brag about huge differences in game mechanics, but I don't think that's necessary.
And another thing is feel of battles.
I think I'll make a very easy comparison:
There. Find me a similary cinematic gameplay footage from Warcraft 3. I surely couldn't.
Units in WC basically stand on the ground a shoot/chop until one of them falls dead. In warhammer, they scream battle cries as they run towards each other, shooting their ranged weapons, when suddenly they meet and their meele weapons clash. They're fighting for a while, yes, if it's just encouter of 2 units pretty warcraft-style, but then sync kills kick in. Sounds like a little thing, but do you know how much it adds to the atmosphere, when you see your assault marine cut your enemy to his knees, then aim his pistol slowly at his head and pull the trigger? example. Don't worry, it's short. Usually, when you watch something, you notice irregularities. Therefore, while watching fights, you see mainly sync kills - and that's another reason why battles feel so naturalistic. Units are screaming war shouts, or just begging for mercy, bodies are flying trough the air, blood spills everywhere... And the game never stops, the battles are endless, there's something happening ALL THE TIME. That's what caught me about this game so much.

BAHAHAHA HAHAHAHAHA HAHAHAHAHA HAHAHA HAHA *cough* HA *Splutter* HAHA HA...
God you crack me up.

[url=http://en.wikipedia.org/wiki/Land_of_the_Dead:_Road_to_Fiddler%27s_Green]Land of the Dead: Road to Fiddler's Green[/url], definitely. It's a crappy, Unreal Engine 2-based FPS but it gave me some good "bus" scaring moments with zombies coming out from the most unlikely places.
Crappy targeting system, almost flat gameplay, easy and predictable but with a great, great atmosphere. It made me think I have to play "everything" by myself to see if I like it instead of basing my views on reviews and word-of-mouth only.....

Audiosurf - I mean, really another shitty rhythm game for PC?
oh wait, this is totally fucking awesome!
Batman - I expected it to feel too much like a saturday morning cartoon, and it did not.
Necrovision - seriously sounded pretty lame, a world war 1 shooter? actually turned out pretty awesome.
Tetris Attack - what is this girly colors and yoshi in the gayest pose ever? zomg it's a tetris game, I know what tetris is without playin tetris 4 girls.
oh wait, this isn't fucking tetris at all, this is some hard core shiiiiiiiiiit.

It was my first zombiegame, and I it's still one of my guilty pleasures.
Also, neverwinter nights. Ruined my social life. I regret nothing.

Funny, Jade Empire is was got me interested in Bioware games - I can't stand Baldurs Gate, KOTOR, or Mass Effect.

Same here. Jade Empire was, for me, mediocre at best. I almost passed on Mass Effect because of that, but I eventually got the game, and loved it. Looking forward to the sequel.

GTA 3: at its release, I had only played a little with the previous episodes and didn't like the series. I saw no goal at playing a criminal who punch everybody and steal cars in the streets. I mean, it's funny, but not interesting beyond 30 minutes of play.
And when a friend gave me GTA 3, well, I just felt in love with the gameplay, the freedom you had in it was unseen so far in other games. And all those missions, I still wonder how Rockstar can create so many and unrepetitive missions (well not to much). And all those details: all the people in the streets, day/night cycle, choose and listen a radio station while driving, etc...