Well, as I've said in a previous post, I'm mostly a DM. I don't have a lot of high level PCs.
Some of my players have gotten their characters up into the early teens. That's about where I prefer them to retire. :)
I think Robyn Hoodwynk made it to 7th or 8th level. I enjoyed playing him.
My current character, Gorsen, Cleric of Lathander, is (at the time of this writing) 7th level. (I'll be sure to edit this post if he dies tonight!)