Which operating system is best for my Mac?

Hello, what operating system do you recommend installing on my mid-2010 MacBook Pro 6.2"? It currently has High Sierra, but that's quite old. I've already upgraded to a 240GB SSD and 8GB of RAM. Based on the image specifications, which one would you suggest? I'll be using it for schoolwork and watching videos, movies, etc., but no gaming. What's the highest-end operating system it can handle without running too slowly and that will still be useful for years to come?