There are a few different styles of RPG's. Torchlight falls into the hack and slash category. It's mostly mindless killing with little story to follow, Torchlight 2 is out, which you may prefer.
You may like more of a true RPG in NWN, as mentioned above. These have much more active story lines, and conversations with NPC's. You also control a party of characters. Dragon Age Origins is the spiritual successor to Neverwinter nights. Mass Effect is a futuristic type of this game, as well as Star Wars: Knights of the Old Republic. The Witcher and The Witcher 2 is more like this type, except you control a single character, rather than a group and a unique combat system.
There is also the open world, single character type of games that aren't quite as epic in story, and leave you to do what you want, when you want. These games usually have a decent story as well, just not in the same category as NWN or Dragon Age: Origins. The Elder Scrolls are a good example of this. Most recently, The Elder Scrolls: Skyrim is a good one, the sequel to Oblivion and Morrowind. Fallout 3 is a post apocalyptic version of this type of game.