My favorite one was a Budweiser one where these two guys were checking out and they had to decide between beer or toilet paper...in case it is somewhere on the Internet and you haven't seen it, I won't ruin it.
Another one that seems to stick in my head a lot is a Tobasco one. This guy is eating a piece of pizza and he puts tons of Tobasco sauce on it. Then a mosquito flies onto his arm and sucks blood from him and begins to fly away and then the mosquito blows up. Good stuff!