With a long-term investment plan from 5 years to -10 years, Bitcoin and Ethereum are the 2 best options, one is the king of crypto, the other is the king of altcoins. But LTC is not a good idea, LTC is one of the oldest coins and in general it is not upgraded and updated often. it is quite old and outdated compared to the recent emerging altcoins. if it were me, I would choose BNB over LTC.