Any alt coin suggestion expect ada.In my point of view of ada still can't surpass ETH in the smart contract field and even if they can make it will be hard to be replace existing eth smart contract eco system.Moreover late coming project like sol even surpassing to ada,all things ada have is the loyal user base and nothing special things in tech
In terms of altcoin hodling I have plenty of those that I am hodling for over a year now and hoping that it will benefit me if I do it long term these are the following alts that I am hodling: XRP, ADA, BNB, MATIC and SOL.