That depends, what kind of RPG? JRPG? CRPG? Action RPG?
For JRPGs you won't find much, mostly Final Fantasy 7 and Septerra Core.
For CRPGs you'll have a much wider range to choose from, such as the always classic Infinity Engine games. I recommend the Baldur's Gate series out of them for offering the best balance between story and combat, but a word of warning on the first it is low level D&D combat which can slightly drag on. If you're willing to skimp on combat a bit Plancescape Torment is great in terms of story. If story doesn't matter and you want mostly dungeon crawling and combat there's the Icewind Dale series which honestly has an excuse plot for why your fighting things.
The Divinity series, Divine Divinity, Beyond Divinity, and Divinity 2, are supposedly good but I haven't gotten to them myself yet.
Vampire the Masquerade: Bloodlines is a good one but might seem too actiony if you want a normal RPG. You would also need the unofficial patch.
If you like any of the Elder Scrolls or Fallout 3 or New Vegas I would recommend rebuying them and seeing what mods can do for them.
The first 2 Fallout games are good, as is Tactics if you want a stategy game.
If you want a throw back to old school RPGs Legend of Grimrock should do it.
Blood Bowl can sort of be considered a strategy RPG, you know like Final Fantasy Tactics, only instead of fighting its a much more violent form of football.
If you need more modern options.....hm. Ask someone else.