My go to Altcoins besides Ethereum would be:
1.Tron
2. Steem
3. Stellar
4.ITOA
5.Bitcoin Origin

PLEASE NOTE THAT:
The last one isn't an Altcoin (yet)  but it is an upcoming project to be more specific it's a multi fork that caught my attention with their Blockchain tech which they are looking to replace PoW with PoA(Proof of Ambassador a greener solution.