Describing a shitcoin varies from person to person. An alt that made you good money doesn't mean that it's a promising one. So please be honest, and if you ever have to sell your btc, what would you buy with them?
My first vote to Monero, for privacy reasons. Fuk ZEC and its "optional privacy" which is NOT a privacy actually. DASH? Lol, no privacy. Another bitcoin clone methinks.
Second one is Ethereum, there is no serious competitor in smart contract area.
I cannot find third one. Maybe NANO.
I can sell a small portion of my Bitcoin for altcoin, and if I'm going to sell it my pick will be Ethereum and Eos I'm very bullish on these two coins, Ethereum obviously is a stable altcoin, Eos is a developing altcoin dedicated to gambling and many Dapps are created within it, but I will never sell all my Bitcoin for altcoins, Bitcoin should always be a top choice for obvious reason.