Matic Solana and Polkadot for me, if I have that much money I'd pack these three altcoins and stake them for long term probably two years which will definitely double my holdings, still this money is way too much for just three coins
Staking is always good, stable coins are good to stake and to find some interesting trustworthy projects. I stake soma ADA, and very soon LFI, LunaFi coin that will launch soon, pretty good project you can check it yourself.