me personally good altcoin to hold during this season is Ethereum, because they are famous concept everyday people launch lately called " DeFi " or decetralized finance because most of them are creating their utility token on ethereum chain, you see that ethereum price having good time pump during this month from 200 to 300 because of hype DeFi project now, also i think ChainLink is good for hold to.
A lot of people choose to invest in old coins, but I think these coins certainly can't bring you much profit. Most investors prefer new potential coins because there will be more opportunities to make money, and certainly if you are lucky you can get 100x assets in a short time. I usually choose coins from IEO projects or some projects in the top 1000 because there are many potential options for you. However, your risk will be very high, and if you choose the wrong coin that can return to 0 at any time.