When I first started to play RuneQuest, our groups characters ended up being extremely powerful. My character, a yellow elf, started his own warrior-subcult of aldrya, my grotaron friend a subcult of Stormbull and a duck started his own dragon cult in Kralorela. That was when they retired. I do have a natural munchkin inside me, and my characters have a tendency of improving fast - but I now prefer a bit more low level gaming, where those 20 trollkins with slings are still dead dangerous.
Talpam, my first character - had divine spells up to a 100 points, lots of lots of strengthening and armoring enchantments. I think he pretty muched defined the term powergaming. That was until I saw this guy:
http://www.runequestrealms.org/worlds/character_sheet.php
He'd pretty much beat the crap out of anything I've ever played!
Sverre.