Stakenet (XSN) is a promising Masternode coin to look into. Given the price at the moment too (very undervalued) you can get a Masternode for just over $2600. Current return on investment is 21%, however once they release the XSN DEX which will be run entirely by Masternodes, the trading fees will be distributed to all Masternode holders.

Check out the roadmap: https://stakenet.io/roadmap/. Developments currently include Lightning Network (on testnet in XSN Discord at the moment), cross-chain proof of stake, DApps, hardware device and the DEX.