Oh, well, potentially scratch that 'un, then!

From what I remember, not in any after the 4th.

If you're into adventures too, Goblins Trilogy has a lot of light-hearted humour and is playable with mouse only. But level codes have to be typed-in when you load the game; unless this is different in GOG versions, which I did not play; but I doubt it.

Titan Quest is in the style of diablo and games like that. All the main movement and attacks are with the mouse. I believe you can view the inventory, map, objectives and everything you need also by using the mouse.

TankPunk: are realtime games appropriate? A lot of the more "modern" games being suggested here have such elements. (And some old ones I might suggest). Is there a level of 'twitchy' that works or doesn't work?

It's easy: Disciples: Sacred Lands

XCOM

Get IT! Dangnabit! ;-)

Not sold here, but I have recently been getting into Eschalon: Book I which is turn based and completely mouse driven.

I also think all games can be played with mouse only ([url=http://www.gog.com/catalogue?search=Spiderweb+Software]Geneforge 1-5 is sold here)

I also like Soldak's games, and if I remember correctly they can also be completely mouse driven. (Not sure about Drox Operative, I have not tried it yet)

Just not too quick, though some games that use some more buttons i can still handle using xpadder. Basically no COD but i can do old doom ;p. Also can do it as long as no button smashing or lightning quick reflexes or too many buttons. Thus able to program face buttons to kb commands or mouse.

p.s. Thank god for on screen kb ;p!

I'm a huuge fan of Dungeon Master, which works entirely mouse only, but at some point in the game the combats become fairly demanding in click speed. As a player i end up using the keyboard (and mouse) to do the few things you can do with the keyboard, which are to move your party and select players.

I'd say in this regard the suggested Legend of Grimrock is even worse. The enemy timing is super fast, though it's not so bad if you play on 'easy' combat.

Others -- can Heroes of Might and Magic 3 be played with only the mouse? I think.... the answer is yes. I'll try playing a game now to see. It's one of my favorites (and turn-based).
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Yeah, just completed a scenario. There's only one thing you can't do without the keyboard, which is to 'spend action points without moving', which is a hack they had to add after the game shipped. If you're standnig on a building you can reactivate it without moving with spacebar. However you can also walk off and on it again at a cost of movement points. The rest is just conveniences like enter to end your turn.

Get the new one while you're at it, too!

It's not an old game, but The Real Texas can be played with only the mouse if you like (aside from using ESC to quit the game).