A few years ago, I stumbled across the little indie RPG title, "Usurper", but I honestly was not impressed. However, recently it has received some praise on the internets, so I thought I would give it a second look.
How can I describe this? The core system is a sort of minimalist thing. Encounter a problem? Say what you're trying to do and then roll on this table. That's it. No modifiers. No penalties. Just roll and deal with the consequences (or rewards). But that table, and its many variable results, and context, make for a game where the story can really go anywhere, and even the GM doesn't know exactly what's going to happen next. And that's exactly the kind of game I like.