BTC is the first choice and the main asset to have for investment. The value is clear enough with that high market cap. Although nobody knows the future, Bitcoin has the biggest chance to rise up and create a new ATH in the future.

If you think it is enough to have BTC, you may diversify again your money into some altcoins with higher risks if you want. ETH and DOT are also my choices. But never follows what other people do. Just make your own research from now.