Two of them have already been mentioned in this thread, but I might as well throw in my two cents:
Surprise
Wizardry 8. I consider this a “surprise” because I had heard about all the problems Sir-Tech was having. The long delay in the game coming out seemed to be a bad sign (see: Daikatana). I followed the word of mouth on the web for a week after it was finally released and it seemed it was getting good reviews, so I went for it. Funny thing, I heard that some packages were missing a CD-ROM so I asked to open my box at the store to check! (All three discs were inside.)
I have to say that I didn’t have any particular technical difficulties with the game, and I found it was lots of great, old-school style RPG fun. A big part of the fun was building a party and developing the characters. I actually played through the whole game twice, the first time with stock characters included with the game and the second time with characters of my own creation. I tried a third time, but I could never get my solo faerie ninja to survive long enough…
I also have to put in a good word for the voice acting, which was great and added a lot of character to my characters!
While I wouldn’t hold my breath for Wiz 9 to show up, I do have my end game saves tucked away in a folder on my computer, just in case…
Disappointments
Baldur’s Gate. I had heard both good and bad things about this game, but since it seemed to be an important milestone in modern CRPGs I picked it up when it was cheap. It probably didn’t help my impression of the game that I played this one after I finished Planescape Torment. While PS:T had a densely packed, interesting world, it seemed like the world of Baldur’s Gate was made up mostly of a lot of empty space without a whole lot going on. It didn’t help either that I couldn’t run, like in PS:T.
I probably would have finished Baldur’s Gate eventually, though, except that my CD drive broke down while I playing it (going through the gnoll stronghold, after Minsc nagged me too many times about it). After I got the drive fixed I simply didn’t feel motivated enough to play it again.
Funny thing, I’m playing Baldur’s Gate 2 right now, and it’s holding my interest a lot better than its predecessor. It kinda makes me wish I did finish the first game, if only to have a character to import.
Bridge Commander. This one I got because I like Star Trek and more importantly because it was made by Totally Games, which created the awesome X-Wing series. Bridge Commander was competently done, but it didn’t have the variety and excitement that the X-Wing games did. I also didn’t feel sufficiently in control of the action to feel like I was making a difference. (I didn’t like the way the manual control felt either.)