unquestionably I would invest in Litecoin
look at the current price:

But in the month of June the price was $130 ( 0.014 BTC )... that's is bad investment, it had a pump just because of the halving
Don't take random peoples suggestion from the internet. You will always get biased response. They will suggest you to invest on coins they have invested on no matter how shit that coin is.
You are forgetting that even in this thread has good advice and opinions, I believe that the person should read the comments and do some research and then decide what to do.
I think it's not completely safe to put all your investment in bitcoin since the price keeps fluctuating so much.
the best investment is bitcoin
BTC 50%, ETH 20%, BNB 20%, Other Altcoin 10%.
About ETH:
Vitalik Buterin Talks Scalability: Ethereum Blockchain Is Almost Fullbecame a very risky long term investment