Back in the olden days (1 and 2e), I was about the only one in my group that regularly played humans. I liked them because they didn't really have all of the nifty advantages of the other races (other than dual classing: 4 levels of fighter with weapon specialization, then mage, baby--lots of hp and emergency fighting ability, and you didn't really miss the 8000 XP).
These days, I actually play a more balanced set--to me, humans are now the best of the races (from a munchkin POV).
We did run a short campaign with no humans (well, no PC humans, anyway): most of the world was dominated by beholders that were working on some Secret Project. The beholders would move in, conquer a region, then send all of the inhabitants to another city; the campaign began in a (formerly) human city, so no humans were allowed. It was pretty nifty, and we didn't miss the humans at all.