expired 50% off Most of The Catalogue at GOG.com (Prices Are USD$3 and USD$5 for on-Sale Games)
This was posted 1 year 5 months 13 days ago, and might be an out-dated deal
There is a literal snotload (hah!) of games on sale at gog.com. Too many to list. Direct link to the games is http://www.gog.com/x11 and the games a USD3 or USD5, depending on the game.
These are all old games spanning the last 20 years or so of gaming.
For me, some standouts for USD3 are: Alpha Centauri, Sim City, Oddworld Abe's Oddysee, Oddworld Abe's Exoddus
USD5: Heroes of Might and Magic 3 (hell all games uptil 4 are available as well as the entire might and magic series), Oddworld Strangers Wrath
It should be noted that the Activision games are only on sale till 26/12/2011.
Whilst some of these are available on Steam, if you like your games DRM free this is a good place to get them. :)
Shipping costs depend on how much you pay for your internets. ;)
They are having some issues with the load all this love is generating so if things go a little wibbly for you, have patience. Usually all it takes is a reload a minute or so later.