I prefer to buy games on a disc whenever possible, but I do like the convenience of Steam. I'm trying to compile a list of games that support steam when you buy the disc-based version. Obviously everything by Valve (I think that I added all of their disc-releases) is already on here, as well as UT3. I know that there must be others. Help me out here?
 
Thanks :)
 
EDIT: MattyFTM pointed out that GB already has a record here.

Metro 2033, CoD Black Ops, CoD: MW2, Dawn of War II and Fallout New Vegas.
 
Those are the ones that came first in my mind.

New Vegas and Civ V 

The Giant Bomb wiki lists them here, and steam support has the list here.

I like buying games on discs in boxes as well. But when they require Steam it seems kind of pointless to do so.
 
Didn't know we had a list on the wiki though. That's cool, although some indication of whether the game requires Steam activation would be nice too. I'll try to add some info for ones that I know for sure.

If you look through Steam and if it says Steam achievements or Steam cloud, then most likely that game will have it. Just like Dawn of War II, Supreme Commander 2, MW2, Black Ops, etc. 
 
EDIT: There's also a few games that don't have that, but offer the download through Steam. Prey is a good example.

Not sure if anyone else has touched on this, but you can add most non-steam games to steam. This will allow you to use the overlay so you can chat with your friends and browse the web, but the steam-works functionality will not be present.