I've been reading through some rules-light RPGs again, looking for ideas, inspiration. Freeform Universal definitely isn't my bag, but I could always go for a good game of Risus.
And looking back through the rules of Risus lately, I noticed something that I'd probably dismissed or glossed over before: character advancement in Risus depends on making a skill roll that gets harder as your clichés advance. Kind of like BRP. I really like that.
In fact, there are really only two changes to the rules that I'd make for the sake of a Risus campaign: I'd use the "Simpler Risus" dice mechanic, more for aesthetic reasons than anything else (it works really well with The One Ring dice).
Second, I'd throw in a little old-school treasure-acquisition-based advancement mechanic. You know, x amount of silver pieces must be spent per advancement roll at the end of an adventure, that sort of thing.
The more I think about it, the more I drift back in the direction of rules-light games, if only because I have yet to find a rules-medium game that actually suits me. There's nothing in rules-light games to offend my sensibilities, because there's practically nothing there to begin with.
(The only thing that really disturbs me about them is that I'm not always comfortable with just winging the spell-casting and steam-tech; but maybe I could referee with a surer hand these days. Oh, well: I won't really know until my current D&D campaign winds down to a conclusion—not likely to happen anytime soon!—and I can move on to trying out a new game.)