Is it good? Is it free of game breaking bugs?

Is it good? Yes, it is extremely good. For what it achieves, you won't get better.

Is it free of bugs? Tell me a commercial game that is free of bugs; of course it has bugs, it was created by a (mostly) two man team.

Thanks, I will definitely play it; I can live with a few bugs as long as you don't easily bump into those that break the game and you loose all your progress.

There's always a simple answer to that: save often, and create multiple explicit saves -- under no circumstances rely on quick saves.

That's a very subjective question: it depends on your likes/dislikes. But if you want to experience Baldur's Gate as it was meant to be experienced, and in the proper D&D setting (AD&D, as opposed to 3.5 ruleset), then the original, without question. My suggestion is to play the original, and then think about re-experiencing Baldur's Gate through the Reloaded mod.

Thanks Hickory! I'll try to pick up Baldur's Gate during the sale.