This was the shortest-lived group I ever got together. The one time I got some folks together for AD&D 2nd Edition doesn't count, because that group never finished a single game session. This one did, but not in the way I expected (or hoped).
After meeting up with some acquaintances in my sophomore year of college, I decided that the best game with which to introduce a new group would be the Pathfinder RPG Beginner Box. After all, it was my introduction to roleplaying games, and the art and design was certainly snazzy enough. I quickly ran into a couple of problems, though.
First, creating characters took way too long. Like, two hours long. This is also why I have never bothered to try running D&D 3.5; a bunch of college students in the Honors program (or equivalent programs at other universities) don't have this much time, and if they did it would be better used playing instead of crunching numbers. We pushed through, though, and got a party of three together.
Second, these players were obviously too used to video games. In the introductory adventure that comes with the Beginner Box, Black Fang's Cave, the PCs can find a wooden toy dragon on the body of a dead goblin. The idea is then to present this toy to the goblin chief deeper in the cave, and he'll let you go freely and call off the attacks by his minions.
Needless to say, one member of the group didn't stop to learn this. Instead, he tried shooting at the goblins as soon as he spotted them. This pissed them off to no end, and thanks to a string of bad rolls (and one player accidentally shooting another one in the head, although I can't remember which it was), I ended up with my first Total Party Kill (TPK).
Henry, Eli, Bob, wherever you are, just know that you will always have a special place in my heart.