What's your favorite tool?

I’ve been using RawTherapee for several years now, but as an amateur there are so many tools I don’t touch. What tool do you find yourself coming back to with almost every photo? What am I missing out on?
(btw, mine is the vignette)

Dear Kyoko.
Well, this is actually a complex question. Every image has its own specific characteristics and you have to deal with appropriate processing. But I’ll just write a list of the basic tools that I always use - usually in shown order:
My Favorites
(1) Processing Profiles: setting my own profile (nach einem Vorschlag von Andy Astbury. Danke Andy für deine hervorragenden Videos!)
(2) Colour Management: - Input profile, customised, - Working profile (ProPhoto), - Output profile (ProPhoto for fine art printing)
(3) Capture Sharpening: ON
(4) Profiled Lens Correction: LCP profile
(5) Lens / Geometry: (different settings)
Exposure Tab
(6) Exposure: different settings, but at least Tone curve 1 (auto settings), Tone curve 2
(7) Lab adjustments
(8) other tools depending on picture character
Detail tab
(9) Spot removal, if neccessary
(10) Noise reduction (customised settings)
(11) Sharpening (after Noise Reduction!)
(12) Defringe
(13) other tools depending on picture character, be careful with Haze removal
Colour tab
(14) White balance
(15) HSV Equalizer
(16) other tools depending on picture character
(17) Wavelet levels (if neccessary)
(18) other tools depending on picture character, be careful with Retinex
Selective Editing
(19) Selective Editing, it’s complex, see videos by Andy Astbury
(20) Crop
(21) Resize
All right, these are the essential tools. Remember, the order of tools and sub tools plays a subordinate role.
All other tools are optional.
Try it.

The sequence does not play a role at all. The pipeline is fixed as you can read here Toolchain Pipeline - RawPedia

The color curves in \textrm{L*a*b*} especially hue by hue and chromaticity by hue.

@ChasingShadows Their favourite tools in order of preference.

The CIECAM modules are pretty fun to play with: they have a life of their own, in constant development thanks to @jdc.