WP Rocket is by far the best commercial cache plugin on the market. W3 Total Cache may be more robust, but many of the features are very difficult to implement and I've run into countless errors. To be fair, they are mostly due to configuration issues, but WP Rocket makes configuration so easy, I can set it up on a site in just 10 minutes with no errors or problems. It has a limited set of "options" but in my opinion, the right ones.

If you're a developer with the time to install and set up one or many free plugins that do what WP Rocket does, then that's great, but for people who want something that "just works" and is well supported, this is the plugin that saves time and works beautifully.