For me it's going to be with blatant advertising in games. For some game it's acceptable (ie: billboards in racing games, the rink boards in hockey) but product placement within games is starting to become abominable (let's go Axe Bodywash and Burger King in Guitar Hero!), and when it turns into commercials within my game, that's where I draw the line. I hate advertisers and marketers as it is, believing that they are the lowest form of human lifeform, and having to pay for games and hae those thrust upon me...well, that will be the last straw.
I already do not watch TV, instead downloading my shows for watching later, I'm starting to despise going to movies, with commercials at the start of them (beyond trailers) and some movies becoming nothing more than glorified 2 hour long commercials in themselves (Transformers for example being one of the larger piles of GM dogshit I've wasted time seeing), I do not want to see video games becoming just another medium for corporate assholes to tell me what I should be buying.
I hate advertising...