Get Dark Messiah of Might and Magic for free.
Simply go to this site - http://www.bgamer.pt
- its the web site of a magazine that is giving this game away for free on the cover but you get the serial number online from them.
It's in portugese but look for the section titled C?IGOS in the list on the right of the site and click on the Dark Messiah link, you'll need to register with the site (what to put in each box is pretty clear) and once you're done you will get a serial code.
Open up Steam (or install it from http://www.steampowered.com/and
under the games menu select activate product on Steam and drop in the serial number.
You should now have a full copy of the game registered to your Steam account.