Bought one game which didn't seem to load, so I went to trade it in, having to give a bit extra money to turn in (pretty iffy store). When I got back, it didn't work! I thought it was the worst luck ever, so I got a third game and said if it didn't work then nevermind! So, another game later and another extra bunch of money, I sat there trying to get it to work.
IT DIDN'T! I actually started crying until my friend fiddled a bit with the TV and realized that we didn't have the console set up properly and we got it to work. So... I enjoyed that third game which was nowhere near what I wanted, but damn it if I was going to go trade it in again. Please don't ask what we did wrong, because to this day I've never seen it happen again.
Edit: The third game was Worms, which actually was a lot of fun.