The Temple of Elemental Evil

You might want to install the mod pack thing

The kablammiest game that ever kablammed. Kablam it as soon as you can.

Hands down the BEST combat in any RPG ever. So many great fights. I replay it every few years just to re-experience that rush. Just make sure you get the community patch. Fair warning, if you're looking for a good story then you should probably avoid. But the combat! OH MAN!

I fondly remember playing AD&D in the Greyhawk campaign world, and I was thrilled when this game came out... Then I realized it was riddled with bugs, had horrible voice-acting, and uninspired background music. But there are some positive points to this game: good turn-based combat, nostalgia, and the challenge of beating it. I've beaten this game at least twice and always felt rewarded in the end. I suppose it's similar to how Dark Souls players feel after beating a hard boss after dying over and over and over again.

If you are looking for classic D&D with 3.0 rules, this is the game to get.