The very first crypto to adopt the PoS mechanism was one called Peercoin. Currently, there are around 100 crypts that use PoS for their blockchains. Some of the most popular ones at the moment would be :
Tron (TRX)
Cardano (ADA)
Tezos (XTC)
EOS (EOS)
Cosmos (ATOM)
Of course, ETH will also become a PoS token soon enough.