I very much want to believe the classic 2 dollar bill at taco bell story (Snopes calls it “undetermined”).
I also was very convinced the first time I heard the one about the groom who put photos of the bride and best man in envelopes under every seat at the wedding, then walked out in the middle of the ceremony…
I guess I feel for the one where the guy puts the JATO booster on his car and ends up plastered on an Arizona cliff wall. But how could you not believe that one? It’s something that’s just so crazy that you know someone is going to do it.
I fell hook, line and sinker for the “syringe/needle found in the McDonald’s playball area”. I remember reading that and thinking, Well…hope the kids enjoyed it, because that’ll never happen again. Several of us at work had received the email from I-forget-who now, and we were just aghast! NONE of our kids were getting back in that ball area! How terrifying.
I think I discovered Snopes the same week (unrelatedly) and realized the whole phenomenon of UL scare tactics. Hey…that one worked for me! I don’t think I’ve been taken in again since then, at least not without a whole lotta skepticism and a quick trip to Snopes first.
Oh, but I do remember our whole building (back in 1993) receiving faxes about the “headlights and gang initiation” UL. We all went into a low-grade panic about that. The internet was “new” to us, and we peons didn’t have access to it anyway. All we could do was…well, not flash our headlights. 
More recently, I believed, as did a lot of other people, that a German couple didn’t know they had to have sex to conceive.
I fell for that one too, then I found out how the rumor got started. :dubious:
I was incredibly gullible in my youth: UFO’s, ghosts, and just about every UL imaginable. Then, for some reason, it all changed when I was about 14. My first step toward the good side of the force was, appropriately enough, Martin Gardner’s Fads and Fallacies in the Name of Science. I then read his other books, and eventually ran across Hal Morgan’s Rumor!, which introduced me to the world of Urban Folklore and shattered some long-held beliefs I’d had. In college I found UseNet and a.f.u (back when snopes was just one of the regular posters). Since then, I’ve been a regular reader of snopes and SDMB, and always check out any weird stories I come across before passing them on.
That said, I still fell for snope’s fake story about KFC dropping ‘Kentucky’ from their name because the state starting demanding money for use of the name.
I fell for the cold war pen story for one day until someone corrected me with the link. I’ve heard it several times since then but I just can’t bring myself to say “um, you’re wrong, look it up.”
I thought KFC did really use GMO chicken? Whatever it is, it’s gooood
When I was a freshman in high school, the bit about gang members hiding under parked cars to slash the back of your heels and then cut off your fingers was going around. And my best friend even had a FOAF story about it happening to someone!
I also believed the one about the woman suing after eating contraceptive jelly on toast and then suing because she got pregnant.
Well, I didn’t fall for that one. Striped or not, a zebra’s head just doesn’t look like horse’s, and that’s just about all you saw of Mr. Ed. However, the Titanic/Poseidon Adventure linkage I fell for hook, line, and (heh) sinker. In fact, that was what introduced me to the IMDb. It wasn’t until I found I couldn’t get from either the D.W. Griffith or the Donald Crisp entry back to the 1911 Poseidon Adventure page that I began to get suspicious. (I’d use the embarrased smiley here, but I think it looks more like it’s yawning)
DD
It bears pointing out that the above is listed under their lost legends, which would explain its “True” status; just to avoid confusion 