As well as LTC, I think DigiByte should be in the mix; at around 0.01 USD, very easy to have a small holding; 15 second block time and 5 mining algorithms...4 times as secure as BTC. Not wide adoption yet; maybe never?

BUT, I have held many altcoins over last 2 years, which are now worth nothing, however.

A very interesting space to play in - and FOMO can tip you in to some poor decisions!