Day 10 - Craziest thing that's happened that you saw
I haven't been playing for a long time yet, but I did have one thing happen that was interesting. I was DMing a game (actually an evil campaign I was running), and one of the players was getting a little overzealous with his ranger about killing things (or attempting to) before anyone else could get close enough to even join in.
Everyone was getting a little frustrated (me included as the DM), and we were playing in Eberron and they were headed towards the Mournlands to deal with something in there. They ended up spotting a Ragewalker which has a supernatural ability called Repel Missiles; which automatically turns any thrown or projectile weapon back upon the attacker. He attacked it full out as they spotted it from a distance, and almost knocked himself out in the process. Needless to say he at least learned to judge his opponent a little before going full out (but sadly that hasn't stuck around for long).
It sounds mean, but it wasn't intended to be, it was mainly meant to tone him back some, which at least worked for a time.