Favorite crypto for currency: STEEM by far because it is free to send, uses simple addresses and is incredibly fast.

As far as a technology I think that there are a lot of competing coins such as ETH, EOS, TRX and so on that will have to prove themselves over the next year but those three coins have the most potential right now for technological adoption and intelligent use cases.

Long term growth I would have to say stick to the mainstream coins that are offered by the big names because they will eventually become the avenues of adoption in the future. For example many crypto traders started with Coinbase so they are most likely going to buy the coins that are offered on that exchange first and have confidence in those investments over smaller cap coins. Bitcoin, Litecoin, Ethereum are the big three in my opinion and they will receive much of the capital in the next big bull run.