Fable PC version was seriously delayed behind the 360 release. Fans (theres one in my house) simply werent gonna wait that long. All employed gamers I know that have $$ for a gaming PC also own a 360 or PS3 (or both), whereas a majority of console owners do NOT own a high spec game capable PC. Makes little sense to release a PC version with such delay behind console release date, especially considering MSFT effectively lost the Fable-PC crowd as Fable2 was 360 only.

PC version before console a different story, so long as it's not so long the game is considered "old".

Fable 3 looks horrendous. I really don't know why they even bothered porting it over, when they skipped the second installment entirely. I'd go so far to say that Peter Molyneux is my least favorite developer ever.

The Witcher 2 seems to be the 15th most sold game on GOG, and 5 of the ones above it are free games (or 6 if you count the Jagged Alliance: Deadly Games stunt). Source: Games catalogue - List by bestselling.