[Nfinity]

Baldur's Gate 1 and 2 were extremely fun and challenging, and excellent predecessors to what is my opinion the best game in the series/genre Neverwinter Nights (haven't played the sequel yet, so my judgment could be a bit off there)

It's similar to Diablo IIRC in the aspects of getting quests, POV, and some level of "free roaming" to the map. The combat system is vastly different, however. You have multiple party members with their own sets of stats, weapons, etc. You move, target, and attack in turns instead of a real time click&slash type of combat that Diablo was based on.

If this sounds interesting to you, pick them up. Likely you can find a Baldur's Gate bundled with BG2 and Icewind Dale. If your not completely sold, I would suggest picking up the first Neverwinter Nights. They are extremely similar, it should be cheap since the sequel came out, and you can judge whether or not you like this type of game without being biased by graphics/ limits in technology when Baldur's Gate came out.