the old might and magic games worked quite fine with mouse only, when I remember correctly :)

The HOMM series, the Disciples series, MOO1+2, the Fallout games, a few others. Depending on how quick your good hand is, you could play many non-turn based games with nothing but a mouse, like hack'n slash RPGs, like Diablo 2, Sacred, etc.(I can play those with nothing but a mouse)

Legend of Grimrock has a mouse only mode which supposedly works very well.

Thanks for replies so far! Do you know which would have most immersive story?

Of those I mentiond - Probably HOMM 2 and 3 and Fallout 1 and 2. OH, and King of Dragon Pass too - Can't believe I forgot about that one :P

The 1992 remake of Hero's quest or alternatively named: Quest for Glory: So You Want to Be a Hero? That's mouse only isn't and has RPG elements.

Can't remember how the Return to Krondor plays. Was that mouse only as well guys?

Also? Baldur's gate / Neverwinter nights etc? Although you might want to pause those games at time to time.

Here are a handful:
Fallout 1-2+tactics
Dungeon Keeper
Temple of Elemental Evil
Ultima 7
Age of Wonders 1-3
Heroes of Might & Magic 1-5
Populous 1-3
Settlers 2 Gold
Panzer General 2
Lords of Magic
UFO-series
Fantasy Wars

Not: Dungeon Keeper, Settlers & Populous are not turnbased or RPGs, but might still work.

There are many awesome suggestions above!

Baldur's Gate and Baldur's Gate 2 are mouse-based, though battle is partially real-time, so it may not work for you. Also, Planescape.

Have you considered point-and-click adventures? Tales of Monkey Island etcetera. How about turn-based strategy? The Age of Wonders series has a pretty good rep, and that's a combination of strategy and RPG. Battle for Wesnoth is also great, and free.

King's Bounty may also suit, I believe.

Looks like good community here, thanks everyone! Also i can use xpadder as long as it only needs face buttons.

Yeah, I would highly recommend Fallout and Heroes of Might & Magic. Also, I think Arcanum uses basically the same mechanics as fallout? Someone is going to have to clarify that, I think — I've not played it.

A lot of games can be played only with mouse.

For a start, I'd recommend the first </span>, properly [url=http://www.nma-fallout.com/forum/dload.php]patched and updated for your RPG needs, and the first Jagged Alliance for your turn-based needs (it is a tactical strategy).

Baldur's Gate 1 and 2 if you haven't played them. When I first got them i used only mouse + spacebar to pause the game. But you can just map pause to a third button on the mouse.

I also think Silver was playable with only mouse, can't remember exactly. But I loved that game.
If someone could confirm silver would be great.

Yes, the mechanics are technically the same, except that turn-based combat doesn't work well in Arcanum.

RPG with loads of depth, huge gameworld and story, can be played with just a mouse.....

Ultima 7

Not forgetting if you get that you also get the Serpent Isle expansion included with gives many more hours play.

You can also play Arcanum with just a mouse if my mind serves me right. Haven't played it in a few month so mind is a little hazy on it. Need to get back into this one myself, stopped playing after losing a few hours play as I forgot to save it!

I also forgot...

Divine Divinity can be played with just a mouse also, set things like potions and spells when selected to right mouse button. Its a huge gameworld, It has took me 25 hours so far to see the entire first map, the town to the north and exploring the sewers under the town, done a good few of the side quests also included in that time. Its absolutely huge and great game to play, kind of similar to Diablo in quite a few aspects