I am not saying that these coins are the best to hold for the long term but I am currently holding these coins and planning of holding them for a long term maybe until the year 2024, these are the:
1.Etheruem
2. BNB
3. XRP
4. ADA
5. PR
I am not an expert but based on some of the research I've done, these are the coins that have potential in the future.
You just need to have a good research and find those important news in regards to any alts that you'll going to invest
your money, the more you understand the more chance that you'll be able to gain decent amount of money out from those
assets that you'll going to keep, Either long or short term everything is possible if you performed your DYOR.