Xeigrich
-Four-string-warrior-
Possibly The Fallout games, and I want to say bioshock, but that's leaning on the diesel punk side.
I take it you haven't actually read this or any of the other threads listing steampunk games?
Fallout is dieselpunk and nukepunk.
Bioshock is dieselpunk and genepunk.
Fallout is also retro-futurism, though it has some things to be considered Steampunk, such as the Duchess Gambit steamboat in Fallout 3's Point Lookout addon, or the Railway Rifle fro mthe same game.
In any case, if it feels Steampunk to you that;s good enough in my book, though if you consider the likes of crackdown or GTA steampunk, then, you have a few cogs loose.