Of course i suggest to no one going all in, but let's see what will be the answers here.

Looking at the current market, caps and prices, I would choose Bitcoin Cash. I don't like it - BCH, but if we speak about gain for 72 hours, then BCH will eat from BTC for sure.
Current price is 0.1747830BTC.
As you suggest, no one must go all in. This is pure fun speculation.