Longest running campaign/gaming group you've been in.
As far as how long we played I can't remember exactly, but the longest running campaign I've played in was my Father-in-Laws game where I played my Psion (shaper). She got to level 24 if I remember right.
The longest game I've run personally is the Evil campaign I'm running currently. Been going for a little while now. We took a big break between playing but have picked it back up now.
Currently the party is at level 19, and are not quite close to the end of the campaign. So it could go on for a bit longer. It will also be my first epic level campaign to run as well, so hopefully that will turn out well.