NEO is the best one here. NEO is really good altcoin that has a promising future like ETH had ever and I believe in its strengths that it will be nice.
i would add NEO to those two as well. the "problem" with ADA is that it is still getting implemented and we have not tested it yet. and with the main net they can surprise a lot of us. compared to the price of the token, as for now ADA has a bigger potential of growth