The original Mafia was just re-released through GOG.com today. This is apparently a part of the 15th anniversary of the franchise. Honestly, this is the first I've even heard that it's the 15th anniversary of the franchise, so I have no idea if there was anything else or if anything else is still planned.

Mafia is just $14.99 (USD) through GOG.com. It should be noted here that the licensed tracks that were a part of the game's original release are not include in this version of the game. You are left with only the original soundtrack. Those who own an older version of the game, including the version that has been pulled from sale through Steam, don't have to worry about this.