All of the ads suck, actually, save a few.
All of the beer ads all suck because they're still doing the "only manly men drink beer" shit, even though we're going through another women's rights wave, so it always seems sexist and the men in the commercial end up looking like a bunch of self satisfied, egotistic yuppies or rednecks.
All of the deodorant ads after the first few Terry Crews/Tim and Eric Old Spice ads suck because they're all trying to ride on the success of the Terry Crews commercials and they fail horribly.
All of the car ads suck because all of them are the same 5 angle shots of a car driving across a non-specific long road while some douche talks about payment plans and loans and then the car does a power slide or something for a final shot. the Volkswagen German engineering one with the medieval slingshot was funny, but that's the only one on, so it gets boring real quick.
All of the infomercials suck because they always portray people as the most incompetent screwheads and then attempt to sell you something completely pointless that will break down and not work the first time you use it.
All of the commercials that start out with some random pop song and don't actually tell you about the product or service suck, because it sin't even trying to get you interested in the product, and thus fails at what it is supposed to do. It's those commercials that you always mute when you can't skip em.
All of the perfume commercials suck, because you can't actually smell the perfume. plus, they desperately try to make up for this by trying to ineffectually turn you on. you see one model, you've seen em all.
All of the other commercials suck because various reasons. Also, they get in the way of what you actually want to see.