I've likely never fallen for one, because the sheer stupidity I see everywhere daily, tricks my brain into believing a lot of people have to be trolling because they can't actually be that stupid.
A great troll was when FC Honda photoshopped Jeremy Martin's face in a photoshoot, despite him being actually there at the shoot, which made it extra weird.
I also remember this hugely elaborate troll thread about some guy asking about powerbands, it was on one of the old forums, Mototalk or Thumpertalk or whatever. It was basically 20 pages of people giving all kinds of advice on purple, camouflage, green powerbands. It was hilarious because a huge amount of people joined in, and every once in a while some clueless member just wrote something like "what the hell are you guys talking about???"
*Anyone but Reed or Webb Crew*