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.
Nano? Well, different strokes for different folks. If I have to sell my Bitcoin for an alt - that will be for exchange tokens (tokens used by exchanges in buying other cryptos on the exchange.) These tokens always perform well and record great ROI.