Been testing Kbin and Tildes, and I like the way Tildes does it. There are upvotes, no downvotes. Instead, there are also labels that can be applied like joke and off-topic. There's even an analogue of gilding via an exemplary label which has an 8-hour cool down and requires typing a brief reason.
Tildes wants to encourage longer, thoughtful discussion so jokes get pushed to the bottom by default. Currently no option to custom sort that I could see if, for example, you want to read funny comments instead—and that's fine.
Point is, a better system than upvotes/downvotes would be nice as a general feature for aggregators going forward.