Bitcoin - It's bitcoin.
Ethereum - My first Altcoin because of smart contract.
Monero - Privacy coin.
IOTA - Huge potential if it works well. Micro-transactions without any fees.
Ripple - It's the bank's crypto. Closest to have real world usage to move wealth around if multiple banks start to implement it.
Stellar Lumens - Ripple needs competition.
Powerledger - just because.