If I have 1 Btc then I'm not going to stay on a single alt coin. It is always a good thing to diversify your capital. I will prefer to choose those alt coins that has good market cap just like ETH, Zec, LTC and Dash. Base on what's happening with bitcoin, I guess these coins will have the ride and it will depend if there are some new alt coins that are going to make some noise.
If you ask me, i will just invest in litecoin and ethereum because those i think those two which is dash and zec will be successful in long term because they don't have enough reputation for the market to last long while ethereum and litecoin already made a good reputation in the market and they seem that one of ethereum and litecoin will be the next bitcoin in the future.