For a long-term investment, Bitcoin and ETH will be suitable, and other coins should be chosen by everyone for themselves, because everyone sees the prospects of different coins in different ways.
I think we have a lot of choices and we should not always focus on bitcoin and ethereum as our main choice consider about if we didn't have a lot of funds and then we can't get the profit from our holdings in a short time.
We must be a wise investor to decide to invest in trusted coins that can bring us a lot of benefits.