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.
Very good advice and so far I still maintain the coins you suggested and among all the coins I hold the most are ETH and BNB, the others I only use for trading and not for storing them long term or for time certain.
What you did I think is correct we need to distinguish which coins to trade and coins to save in the long term,
with proper management it becomes a positive step and may be able to provide maximum profit as well,
Ethereum and BNB are two unquestionable altcoins and are perfect for the long term