I like Baldur's Gate and Baldur's Gate II, but not without reservations.
For one thing, I utterly despise the Forgotten Realms with every fibre of my being, so I can't ever completely ignore the sadness of seeing the effort put into BG wasted on FR. Put that game in Greyhawk and it instantly becomes 50% better.
The replayability of BG is also overrated. There's basically a good path and an evil path, and not much in between. Neither path really precludes you from doing all the side quests. I have replayed it once or twice, but there's no way I can enjoy it unless I allow three or more years to pass between replays, which means I'll probably never do it again.
It's also difficult to ignore the fact that BG led to NWN, which is a really horrible stinker in which it was decided to take everything good about BG and make it worse. And I say this as some one who has played NWN more than I like to admit, searching for user-made modules of quality.
If anyone is interested, the only ones I found that were capable of overcoming the ickiness of NWN were made by Stephan Gagne; his potfolio is good enough that I'd recommend it to anyone. It's the only reason the money I spent on NWN wasn't completely wasted.
FO > FO2 > BG > NWN = a worsening trend.
P.S. Delete Minsc from BG and it instantly becomes 30% better.