I'm not gonna say these are the best games ever, but they're OK, the second one is actually pretty good and they deserve to be played like they were supposed to be.
If you're going to play through all of them, get Baldur's Gate Trilogy so you can use the Baldur's Gate 2 engine for everything, which makes it a lot better.
The first game is boring and empty, though, and the second game degrades quickly after the first big chapter.
For BG2, you can download a fixpack and a tweak pack there. It fixes numerous bugs and permits a good customisation of the game to your liking, cosmetically and rules wise. http://www.gibberlings3.net/
I have a modest little tweak pack for the first BG that I made myself since G3 don't have one. Max HP per level, guaranteed scroll scribing, bigger arrow stacks, that sort of thing. I could put it up if anyone's interested.
There should be a a BGI NPC mod that sort of develops the party characters relations further by adding some more dialog, personality and quests. Last I checked the mod was lead by domi