
If were going to talk about great cRPGs, we must include Temple of Elemental Evil. This game is definitely a diamond in the rough. But with a bit of polish, very worth it. I was one of the best RPG experiences I've had. Though I've never been to the pen and paper type game, I would say this is the closest thing to the tabletop you can get.
I bought this game for $10 in the back corner of a game store. I had just come off my Neverwinter Nights run through and I was jones-ing for some more D&D. When I popped it into my computer I was hit with a show stopping bug right away. I could not loot the bodies of my fallen enemies. Crap. I couldn't get a patch for it right away (long story) so I shelved it for months and months. Played Morrowind and other games and just forgot about it. One day I had a long stretch of time on my hands so I popped it back in. Best choice I could've made.

Just reading the manual is intimidating. They had to cram a lot of the 3.5 ruleset into a small booklet. Definitely not for the casual gamer, but I enjoyed the complexity. It definitely adds to the replay value with the many combinations of characters you can develop with the use of Feats. Take Joe Generic Fighter. Okay, you could do a sword and board, or follow some feat trees with Spring, Whirlwind Attack and Trip and make him a Spiked Chain fighter. Or go Dual Wield with a few levels in Ranger, or go Two Handed, or so on and so on.

There are nine, count ‘em, nine different story starts depending on your parties alignment. And you will meet and affect the story differently depending on your alignment. There are plenty of dialog choices to make that have far reaching affects to the game (think Fallout). At the very end you are treated to a nice epilogue of what happens to you and characters you have encountered along the way. It varies according to the choices you have made during the story. You can have everything from a goody-two shoes attitude to vile scumbag. The game doesn't railroad you into one way of play. The beginning story can be a bit bland. Simple, in-town fetch quest abound to those with patience who want a beginning XP boost. But if you want to jump right into the action, be warned - this game will gladly slap you to the ground if you are too naive and gung-ho. There are a wide variety of monsters from the typical ghouls, goblins and bugbears to the weird elemental plane creatures like Deep Eyes, Effreeti and Gorgons. Even some gods and demi gods thrown in for good measure.

The combat system is a fun, tactical simulation that was meant to be in D&D. It's not just a "boxing smoker" stand and bash fest like a lot of RPGs. You have to think. But it is turn based so there is time to plan. Power Attacks, Feints, Flanking, Attacks of Opportunity, Ready stances, 5-foot Steps, Charge Attacks are just some of the choices to consider when engaged in battle. And somehow it all done without a grid map. It can get intense. And that is nothing compared to the level of magic use. The Magic Users have a hole arsenal of spells straight from the core rulebooks. There are all kinds of buffs, blasts and battlefield control spells. The magic spell effects are some of the most beautiful I've seen in an RPG.
This game flopped when it came out due to the bugfest that seemed to plague every Trokia game ever made. But, it has a dedicated cult following.
The vanguard of that cult is the Circle of Eight:
Cirlcle of Eight Forum
If you plan on playing this game, SEE THEM FIRST.
You will need their patches. Not only have they fixed the laundry list of bugs that Trokia missed with the official patches, but they have lovingly modded the game to add new twists. They've added new weapons, armor, areas and quests. Would you like to use the character portraits and voices from Baldur's Gate or Icewind Dale? They have them. They also have great advice and strategies.
I hope you will seek it out and give it a try. They just don't make them like this any more.