My vote goes to Luvs "Poop There It Is." (Actually, to make things even worse, Luvs calls the spot "Blowout Championship," which I can't even deal with.)
I'm not sure how Consumerist readers arrived at "worst" in some of these cases. Geico's "Smart Phones, Dumb Things" spot I found extremely annoying, but I give the company a pass for so many other pleasing spots. Samsung's "Spider" ad for the Infuse 4G was just overly loud. The AT&T spot I didn't find bad, but it did make me feel awful because I found myself rooting for the guy to lock his wife in the greenhouse without food for an extended timeout. The Summer's Eve spot? I'm not a woman, but I gave it points for creativity. How else are you supposed to advertise such a product?
There are other categories up for vote: Most Grating Performance by a Human, Group That Ought to Go Its Separate Ways, Most Irritating Animated Actor, Worst Abuse of an Existing Song, Original Jingle That Should Be Junked, Creepiest Commercial of the Year, Celebrity Who Could Probably Use A New Manager Right Now and Trend That Needs To Stop Being A Trend.
How the "creepy" category left out the "People Person" ad for the Toyota Prius is beyond me, but it deserves a special write-in vote.
A complete list of last year's winners can be found here. Staples' "Wow! That's a Low Price!" took top honors in 2010.