I do not rally against the idea of in game advertisements, because in many of the situations I've seen them done their placement is entirely realistic. Watch any American Sporting Event and you'll find advertisements worked in at every turn - the stadium is sponsored, every available visible inch of space is covered in logos, analytical segments have sponsorship tags and every two minutes a commentator mentions yet another sponsor. Thus, when I play fight night and am forced to fight in the bout sponsored by dodge, being forced to watch a Dodge commercial actually helps the game seem more realistic. However, after completing the burger king sponsored bout, the fact that you can get "The King" as a trainer (he trains "heart" - a statistic that measures how quickly your health recovers among other things), I am annoyed because it is completely out of place. When I think "fitness trainer", you can rest assured I do not envision fast food icons (Ronald McDonald teaches agility, Wendy builds stamina!).
In other games, seeing advertisments for real products on billboards hardly bothers me because again it helps the game seem more realistic. Seeing a stretch of roadway without billboards seems utterly alien, and if you're going to put them in, you might as well use existing products and make some money doing it.
If properly done, ads don't bother me - afterall, as an American I cannot go anywhere or do anything without being assaulted by a marketing campaign; it's a part of life.