As some have already said in this thread, there aren't games I won't buy because I don't like something the developers did. Ubisoft makes good games, whether or not you like their policies (I don't care for them). EA/Bioware have things like Mass Effect, and Origin doesn't bother me too terribly much.
DLC? Doesn't bother me. I don't have to buy it, after all. Things like Arkham City, where you have to buy it new to get the Catwoman part or pay some money to buy it online. I just wait until for the price of a new copy to go down, or I get a used copy and then buy the DLC if that happens to be cheaper. Most DLC you do not have to buy. Map packs, skins, etc., are just icing on the cake for those of us who want to give extra money to the developers so they'll make the sequel or those of us who actually do derive enjoyment from playing through a game with, say, Hope dressed as Ezio Auditore or whatever the DLC for FFXIII-2 happens to be.
However, sports games and most FPS are things I will never buy, because I dislike sports and FPS games always give me the feeling that something is sneaking up behind me.