Sexcoin. It's the only one so far that has a massive global industry waiting to make use of it.
Sexcoin had a huge runup when it got listed at coinmarketcap.com. Now it is down again and seems to be finding its price, but still 15x where it was a few weeks ago.
There seems to be a real team of committed people that have come together (grassroots) to promote and develop the coin after the original developer abandoned it. They are supposedly integrating video chat (think camgirls) into the software. That feature alone might spur adoption in the industry.
They have a fairly active forum (for an altcoin) that I won't link to here, but you can google it up if you wish. That demonstrates there is community.
They are presently holding a contest with a seriously large prize (enough to buy a car) for whoever promotes SXC the best. There is another thread about it. To me, that shows they are more serious than a lot of the alts.
So I believe there is potential. What is needed now though is for one or more performers to start accepting SXC. If the sexcoin promoters can pull that off (maybe they even handle the exchange for her) we may start to see real adoption and growth.
my $.02. I am long SXC.