Litecoin.
Still below $50 per coin. Likely the first alternative cryptocurrency, created in 2011. It's creator, Charlie Lee, just quit his role at Coinbase to focus on further development of Litecoin. Litecoin will have 4x as much coin mined as Bitcoin, therefore a barometer of price potential (should demand be equal) is 1/4 the price of Bitcoin. Today that would be $600...so from that perspective Litecoin has yet to see its day, therefore you haven't missed much.
I agree with you, that litecoin is a good invest beside bitcoin.
Litecoin has been around for a long time. Its one of the first Altcoins in existence.
Litecoin has the second most secure blockchain, next to Bitcoin.