One that I really hated 2 years ago was the woman president of trek travel posting how she had been noticed by Lance Armstrong's group and she was going to tour de France with them. I was so inspired by her words I fell for it. Finding out it was a farce made me nearly not purchase the Trek 7.7 I had on order. I was so mad. To this day I steer away from trek products because I haven't gotten over the mad part.
Timbuk 2 was advertising a backpack you could put a really big dog into and carry it on you back while biking. I thought it was absolutely ridiculous because I have a dog that size and would not even consider carrying him unless he was sick or dead! I liked the dog though , the one in the April fools day ad. Now if they could make it (him/her) available that would be another story!