I've been off re-reading the RPG.net thread on the subject. It's gotten a lot bigger since the last time I read it. Man...
Actually, I have had my fair share of creepy, smelly, awful gamers. Like the guys who were trying to run credit card scams in the days before credit card security got really tight. Or the guy who would stand there with no shirt and wipe the sweat around his pasty torso...just move it from one part to another, then back again...
eew.
But the best story I have I've related before on these boards. It's kinda gross, so if you're squeamish...
It's actually one of the guys who was involved with the credit card thing. He was on welfare and had no prospects of ever getting off his fat, smelly butt and getting his life on track. I'm sure most of you know the type (nothing against the honest people who end up on welfare, of course, I've been there...then I sent in my $30 to Bob, and now I'm rich and married

)
Anyway, his apartment was a room in a basement that had a kitchen and bathroom shared among a few bachelor units. It was tiny, and full of porn and trash and the eye-watering smell of "used" tissues that have sat around for months. I and my friend used to go there because we were just kids who needed some friends to game with, and dude did nothing but play RPGs and computer games. The voluminous pornography collection was also somewhat compelling for a couple of 15-year old boys. We basically figured the guy was kind of gross and creepy, but that's it. We could put up with his ickyness if it meant we got to kill some orcs with the gaming group (which contained a whole circus of colourful characters...I'm sure my mom used to fear for my safety, but at least I wasn't on drugs or anything).
So one day we were sitting in the guy's apartment chatting about video games, and he excuses himself to the restroom. When he leaves, my friend, for reasons I'll never know, reaches over and opens a dresser drawer. Inside, we see all these cut out pictures on glossy magazine paper. Looking closer, we realize that they are cut out of Sears catalogues, and are specifically the underwear models for the children's section of the catalogue. All very carefully snipped out in silhouette from the catalogue. Prepubescent boys and girls in underoos and whites. Our blood ran cold.
We carefully and quietly closed the drawer, excused ourselves at the earliest opportunity, and vanished. We didn't kick him out of the gaming group, but we kicked ourselves out shortly thereafter. It was actually the more expedient way of fixing up the situation. Let the bizarre creepos have their game, and we'll survive without it somehow until we find some more friends to game with.
Eew. Eew. Eew. I must go bathe now, to get the memories off me.