hello good question. but my personal opinion Litecoin is good option.litecoin is already available in Coinbase so this is really good achievement. i not said Monero is not good option but Litecoin growth level is very high. so l like litecoin
IOTA is very strong cryptocurrency.it's growth is high because when IOTA lauch it's price is 0.61(Jun 2017) something. now 3.85.means growing very fast.soon it's availble in BITTREX exchange so huge chance to increase. IOTA hit $20 in near future. .