You can check out RPGMaker XP or RPGMaker VX if you specifically want to make an RPG that doesn't depend on another game to run (Like the NWN Aurora Toolset).
I would honestly recommend
Game Maker though, it seems to allow a lot of freedom in creating the type of game you want to make, and it doesn't cost much to upgrade to the "pro" version. It's possible to create pretty much any genre of game using Game Maker. Multimedia Fusion 2 is pretty good too.