My portfolio is now packed with ETH, LINK, ADA, LTC and this undervalued token called PAYB - the token of Paybswap.
ETH, LINK, and ADA are good choices. I also have these coins, but prefer to plan more buying for ETH, ADA, BNB, SOL, and DOT. For a long-term investment, you are better to buy those coins that have big market caps. Just avoid the coin that has a low market cap, especially a new coin. We don't know the future of the new coin, its future is very unpredictable.