So I broke my hand...

Bad Rats: The Rats' Revenge

Too much of cleaning Your magic wand, Gandalf ? ;)

Any game where you simply really need to jump and run (looking at Super Meat Boy and Limbo here - but there is probably loads). Strategy games if you can use the mouse left handed or know all the keyboard shortcuts (turn based ones would be easier as there is less rush). I noticed you said Civ V was driving you mad... Try getting all 227 achievements in it?

Puzzle Agent, one of the games i enjoyed most.

Walking Dead and Dungeons of Dredmore

XCOM?

Also, not on PC, but the Layton games.

Don't Starve

get a razer naga and play tl2 =D

Complete a one-handed "hardcore" playthrough of "The Typing of the Dead" and you will never need to buy another drink from now until the release of Half Life III.

hmm,hmm,hmm,hmm,i say,umm,play,umm norhing :D

Super Hexagon.