Jet Set Radio, Golden Axe, and Hell Yeah! Wrath of the Dead Rabbit. Plus more.
Read more here.
All of this is part of the spoils from the "Make War Not Love 3" event. During this, players unlock free games by putting time into Dawn of War II, Total War: Attila, and Company of Heroes 2. Later in the week, Streets of Rage II, Binary Domain, and Condemned: Criminal Origins might also be free if some people go ahead and make more war.
Grab Jet Set Radio and more here: http://store.steampo....com/sub/94153/
Also of note: Jet Set Radio along with some other ports are here @theportingteam