The audit tab (whole lighthouse family),Network tab, React developer tools, Application tab (when working on specific to clientside storage), Cookie editor and Rest client. Out of these my favourite is Cookie editor! Previously, I was bit more into firebug for firefox. Its been quiet a while since I use it.

The Redux DevTools. Being able to see the state at any given point is a godsend, and the "time travel" feature feels like magic.

My most used tool, by far, is the debugger, in any language. Imho, it's the most essential tool to take a peek into a running application to identify logical errors. For example:

By your list of tools, though, I think you mean inside the browser dev tools, right? In this case, in addition to the debugger, it's probably the networking tools and storage overview. The networking tab gives me vital information about what was loaded, if it is cached, how long loading took, what frames a websocket sent, etc. The application tab gives me insight into the data my application stores inside the browser, which is important. It allows me to view, modify and delete the data and test stuff this way.

I arranged my tabs like this: