Monero for short term at least. Lots of people use Monero already. It's one of the few cryptos that are almost exclusively used for a specific niche market. The dark web drug markets.

Whatever your opinion on the dark web and dark web black markets may be you still can't deny that Monero has a use case today. Most of the cryptos that are used past speculative trading are used mostly as alternative payments to fiat. You can go to some online store, find a product you want, and they have the various credit card payment options and possibly btc/ltc/eth options for crypto. So there is not a necessity or a need to buy crypto really yet. With the online black markets the only way to buy and sell goods is to use Monero. Like it or not, the dark web black markets have given us a crypto that is utilized pretty heavily for the buying and selling of goods.