There are so many crypto currency right now. BTC no doubt is the best cryptocurrency to hold since it applies in lots of areas. You can buy games on Steam platform and you even can use it to pay your DMV registration fee. However, right now it is so expensive.
Instead I think ETH, XMR and EOS are really good investment. These currency double easily double, but for BTC, it looks like not that easy.
ETH is now popular for cryptokitties and this blockchain game takes a lot of resources in ethereum networks, I would say people will keep using money to buy ETH to play this game, and ETH price will go up with the demand.
For XMR, many celebrities accept this payment for their songs, should and will go up with the time.
EOS, I believe after the ICO finished, the price will goes up dramatically.