The funniest scam someone tried against me was a guy I met on a plane. This was a) before 9/11 and b) when flights were less than half full and moving seats wasn't an issue. I noticed him because he was good looking, and was flattered when he chose the empty seat next to me (after asking if I minded company). So we chatted, which meant mostly he would say things like "You're really interesting, I want to know this and that about you" and then proceed to talk about himself at length.
It was amusing, but it definitely made me switch from thinking ooh cute guy! to wow so conceited. As it happens, he was on his way to a motocross competition, but his day job was something involving fancy sports cars. And as dumb luck would have it, when he dropped his latest sports car off, he had left his wallet in the glove compartment, with his driver's license and credit cards and cash. How unfortunate!
(I recall wondering how he got on the flight without ID, but I didn't ask him and it was before 9/11 so it's possible they still accepted other forms of ID than driver's license.)
So he spends the last half hour of the flight dropping hints about how tough it was going to be for him to get to his motocross event 2 hours away without a rental car... or a ride from a kind stranger... After we landed, he kept up the hard sell and I, ever the problem solver, suggested he go to the police office in the airport to get a copy of his license but that wouldn't work, for some reason. He wandered off and that was the last I saw of him.
Until he showed up at the car rental place shortly after I did, with a new girl in tow. He told me proudly how she, kind stranger that she was, was going to rent a car for him! Oh my. All I could think was about how he had wasted 2 hours on me for nothing, and managed to find a new mark *and* get her to rent him a car in less than 10 minutes.