To me Mina and Zcash are interesting since they (plan to) use cryptographic arguments to show that chain states are valid, which leads to some nice features, such as better light clients. I'm probably biased since our own startup was influenced by them. Besides that, I'd say NEAR since it seems like the most promising sharded chain that's in or close to production.

(They weren't on the list since Mina hasn't launched quite yet, Zcash isn't PoS though it might switch, and NEAR isn't PoS in its current form, but will be soon.)