Same here. I had a small advert for a movie for my PS3 copy of Deus Ex: Human Revolution, but it was so small and just in the loading screen that I couldn't really care. It wasn't like it drew the loading screen out or anything.
I think a lot of companies have yet to find a way to deal with the rising cost of making games that doesn't fuck the consumer over (DLC I mean). In game ads could be a good way to do that, if done tastefully.
If a game had straight up commercials or "Have it your way" loading screens, I'd have a shit fit but if a game has billboards and radio ads for made up companies and products in the background, they may as well be for real things and help absorb the cost of producing a game.
I don't really like it, but it can be more or less acceptable depending on the genre of game. Like if it was a nascar game, then sure I could see advertisements in it. Even games like GTA or other such games that are supposed to take place within the "real world" I could see, yet would probably throw me off a little.
Also this discussion reminds me of Code Geass, otherwise known as the most elaborate Pizza Hut commercial on the planet.