DotEmu is giving out a game free each day until 5th June 2011 (EU time).
The current offer (deal dated Wed 1st June) as I write is a classic PC game called "Gobliiins" worth EUR2.99 (~AUD4.10):
http://www.dotemu.com/en/download-game/44/gobliiins-1
List of other games to be given away can be found on this link:
http://www.dotemu.com/en/the-store-dotemucom-celebrates-its-…
I'm assuming the Wed's offer is going to expire very soon (EU time), so if you like "Gobliiins", get in quick before the offer is replaced by the next day's deal. Note that this game is only for the Windows PC platform.
DotEmu specializes in finding classic computer games from the past thirty years, and more. The adapt, reprogram and emulate where necessary to allow the games to run on modern devices. DotEmu claims that all their games are DRM-free and allows for re-download, similar to another games site GoG.com.
Enjoy!