By most promising coins, do you mean coins with the best projects or coins which can appreciate in value in future? I think everyone has coins and tokens he or she considers cool on their portfolio. Actually the coins I decide to hold for long term are my most promising coins, I think same holds for other people who do due diligence before holding and not holding coins because others are holding.
I had the same questions in my head. I think that there is no cryptocurrency that would be the most promising, they are complete and each project meets its objectives. For me, the benefit of the coin is primarily the possibilities that it provides at the moment.