IMHO the only really necessary and useful stablecoin is DAI. Instead of being issued by some dubious piggie, the peg is maintained by a smart contract. DAI gets far less publicity than Tether for this reason.

It really goes to show what percentage of crypto bros care about decentralization whatsoever. Tether has a market cap of $184B and is the #3 "cryptocurrency" as of this writing. The dump hasn't even happened yet!