I'm probably forgetting some but here are the main ones I know of: - Idera - Red Gate - SQL Sentry - Dell (Spotlight/Foglight?) Which is best? It depends what you're looking for so that's not a question that can be answered here. But they're all reputable products so I'd suggest you look at the features and see if they seem to cover all your needs. Then get a trial version of those you like the look of, and see what they're really like. If they won't do you a trial version, I guess they don't want your money!
Have a try dbForge Monitor -
https://www.devart.com/dbforge/sql/monitor/ It's a free add-in for Microsoft SQL Server Management Studio, that helps in monitoring and analyzing SQL Server performance and helps to save your time.