Advice on where to invest the rest of my savings budget

Every Friday of the month I put $150 into QQQ. This is just a reoccurring investment that I have set up.

I have an extra $280 to work with every month. What is a good stock that I should target? I know I should be diversifying my portfolio, but what’s a good stock that is different than QQQ and still has consistent gains over the years?

Thank you in advance.