Amber (or AmberDicelessRolePlay?) is truly diceless - everything is by GM fiat. Nobilis? is also by GM fiat, but has slightly more in the way of stats and resolution mechanics than Amber. Rather interesting background too.
Quite right, I forgot about that one. Although there is enough 'my number is larger than your number' to count as a system, really. --Vitenka
EverWay sparked this page off. It uses interpretation of a tarot draw. OverTheEdge isn't - but it usually plays that way. How often do you need to roll dice to see whether being the embodiment of peoples waking dreams beats the power of lobster? DeadLands sort of is - it uses Poker as a resolution mechanic. And there are a couple that I can't think of the names of right now which use RockPaperScissors.