4. Edition re-releases
In theory, repackaging your game as a comprehensive edition--Game of the Year, Definitive, Legendary, whatever--is a huge service to players, and an excellent marketing move. Your slightly aging game becomes immediately relevant again, with a better-than-ever deal for players that skipped out on the original release. And with an attractive new price for all this excellent content, you're bound to attract an onslaught of new buyers.
In practice, these editions are indeed great--unless you're an early adopter, in which case they become a violent kick to the proverbial stones. You know that game you paid $60 / £40 for, plus all the DLC you bought at $10 / £8 a pop? Yeah… now we're offering all that content to everyone but you for a mere $20 / £20. Oh sure, they had to wait a few months--but thanks to you giving support early on, they get all the benefit! You, on the other hand, get nothing but buyer's remorse.