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?
I'd go for Monero first, and probably for Litecoin in second, then XRP in third or Ethereum. Monero, Litecoin, and Ethereum are the big threes that proved already their existence is worht it for someone to invest their money on it, if bitcoin is the king, then these 3 are bitcoin's General.
First of all, I will not sell all of my bitcoin to an altcoin because it is not the way that I diversify my portfolio
OP didn't mentioned that he will sell all of his bitcoin to buy altcoins.