What's the best business to do with $150,000 ?
The best business is one you can control combined with a good idea. Junk shop maybe.The banks will pay small interest just now. I get 7% at a credit union in South America.
Do what you love, otherwise you won't want to work hard to make it a success.
Nobody knows.. .just start one and if it fails start another....I am not a business professional and this is not professional advice.
Start your own company, Maybe something on the Internet.You have to find ideas and sketch them, maybe you will find an idea of making a product that doesn't exist yet.