Actually a very amusing battle happened just this week.
The group I'm playing with has just entered Epic so what I'm about to describe may sound a little power mad, but anyway....
I'm playing a Paladin of Bahamut (with 12 levels of Dragon Disciple) and we were in the middle of clearing out an infestation of demons from Elminster's Tower (Elminster has gone bad in this campaign, and currently is nowhere to be found, hence us wandering around his tower looking for him). We had just come across a corridor that ended in a T-Section with huge rooms leading off each side. After the wizrd of the party sent his familiar to investigate it came back and reported that each room was packed almost solid with Vrocks, Bebiliths, and various other demons, with the Vrocks attempting to summon in more demons. When I say chock full, I mean close to 80 Vrocks on each side, 4 Bebiliths and a couple of other nasties in each. The group decided that we would be annihilated if we attempted to fight both at the same time, so I decided, out of sheer Paladin style honour, that they should send me int one room to keep those demons busy whilst the others fought off the rest, locking me in with the other demons with a wall of force. My 'friends' decided this was a fantastic idea, and sent me off to fight.
Amazingly I survived the fight, with copious amounts of 1-shot/charge item usage, and they managed to take care of the otehr room without too much of a problem. I think the DM may have made it slightly easier on me though, because no-one should have survived that fight.
Oh yeah, it was an extremely fun fight, can't tell you how much I enjoy having reach and Great Cleave.