If you could only invest in 1 alt coin what would it be?

I have a small variety of alt coins in my portfolio. I am new to crypto and have been researching and buying into what I believe are good investments. My education on crypto as a whole isn't anywhere near where it needs to be.

I am looking towards the future and don't have a lot invested yet. Maybe around $500-$600. I invest maybe $30 per month as I don't have much disposable income at the minute. So I've been trying to invest in alt coins as a way of buying low and hopefully selling high in the future.

I'm not looking to become a millionaire (although I wouldn't say no). Financial freedom is my aim and them eventually get my 4 kids into crypto and giving them a life of financial freedom that I wish I had the opportunity or knowledge to have.

So what I'm asking everyone here is :

If you were just getting into crypto, having done some research on alt coins, but could only invest 100% of your money into 1 of the coins ypu had researched, which coin would you choose?

Edit:Spelling