SEMRUSH – (FROM $69.95/MONTH)
This is my favorite SEO tool and it has become the cornerstone of all my keyword research. SEMRush allows you to find all your competitors best keywords with the click of a button. My favorite feature is using it to see which keywords my own websites are ranking for in the top 20 spots in Google search. I can then choose valuable keywords to work on improving rankings. It’s often easier to improve rankings for keywords you already ranking for than starting from scratch.
The tool is kinda expensive so I usually just sign up for a month or 2 at a time, do a big batch of keyword research, and then cancel my subscription until I need it again.