by Sam & Max 104: Abe Lincoln Must Die!: steam://install/8230
America's Army 3: steam://install/13140
TrackMania Nations Forever: steam://install/11020
Peggle Extreme: steam://install/3483
Probably everyone already knows this, but if you have an ATI graphics card you can get these games for free:
Half-Life 2: Lost Coast
Half-Life 2: Deathmatch by going to steam://hardwarepromo/305
If you have an nVidia card you can get the above two games plus Portal: First Slice by going to steam://hardwarepromo/609
Lastly, you can get Speedball 2: Touramament for free by going to http://www.cdaction.pl/seriale/speedball_2.
It's a Polish game magazine, and you'll need to make an account. If you follow the link above you'll see this screen:
Click the orange link in the top-right to start the registration. This will take you to this screen:
which is the standard 'I have read...' checkbox and continue button. Next is this screen:
First section on the left is your desired username, under that is for the password and the password confirmation, under that is the email address and confirmation.
On the right are two checkboxes for accepting email from admins (top) and users (bottom). Fill in the Captcha and click the button in the bottom-right.
I registered with a Gmail address and the key arrived in about 30 minutes. In the meantime I changed my address to my ISP-given one and got the key immediately. YMMV.
This page contains all the links to currently offered keys, but I believe only Speedball 2 is for Steam.
