Apart from Ethereum, Litecoin, NEO, Waves and others, my best alts are those that stands for real life uses. Especially alts like:
-Swachhcoin: Aim to be the world's first waste management platform on the blockchain
-MiracleTele: A digital means of connecting millions of people from all around.
-OmiseGO: Revolves around providing super-fast payments and linking e-wallets for different types of fiat and digital currencies.
Seriously to me, these are among the best altcoins