In no particular order, Vivaldi, ironfox , duck duck go, librewolf, Firefox, chromium. All for different reasons and things.

Adopted Vivaldi across devices. Firefox is also good

Firefox

Zen Browser.

LibreWolf (Firefox fork)

Librewolf on my PCs, IronFox on my GrapheneOS phone

Firefox

My employer pushes custom certs to Edge and Chrome for their internal sites, so I can't use firefox exclusively🥴.

Zen browser at home, with firefox as backup when Zen breaks, which it seems to do with some frequency.

Waiting patiently for Ladybird🙏

I use helium, based on a recommendation from a user here. I used to use brave, but the peter thiel aspect made me ick.

About 6

Stock Firefox.

Floorp

Librewolf, Vivaldi, and ungoogled chromium on desktop.

Waterfox, Iceraven, and Mull on mobile.

LibreWolf on PC. Like Firefox but with stronger protections and I love it. I used Firefox for years, but growing concerns over AI integration and Mozilla made me try it, and I'm not going back.

IronFox on Android. Works great, has good privacy controls like LibreWolf does, and websites work. I used to use Cromite, but switched due to ethical concerns over chromium and the fact that many websites were broken on that browser, even after enabling JavaScript and cookies. I was basically locked out of my college Microslop account because login was broken until I switched. Also, go to hell Microslop.

Edit: Also Tor Browser on both PC and mobile. I hate using it on websites with ads though (like seriously, how can anyone without a blocker handle such a bombardment day to day?), so I often use LibreWolf or IronFox instead.

Zen Browser. At this point I'm using it almost exclusively for the glance feature, which loads a page in an overlay above the current tab. This is incredibly useful in webmail for short-term page visits, like email verification links, etc.

Waterfox

Two browsers in my android phone - Firefox (routed through Mozilla VPN) for anonymous browsing, and Ironfox (excluded from Mozilla VPN) for logged-in browsing, e.g. banks and social media.

But just one browser in my windows device - Firefox, since windows Firefox supports multi-account containers, and it's compatible with Mozilla VPN, so I can do domain-level inclusion/exclusion.

And of course I have the usual protections in each, I.e. uBlock Origin, LocalCDN and the like.

Desktop: Waterfox, Ungoogled Chromium

Mobile: Ironfox

On the desktop, I moved from vanilla (but hardened) Firefox to Librewolf to Floorp and then to Waterfox. Ungoogled Chromium is for the times some stubborn website refuses to work with Firefox (and its forks). For mobile, I only have Ironfox and if websites don't work there, I just get my ass to the desktop.

Qutebrowser. It's a bare chromium engine (QtWebEngine) with some very neat vim bindigs. I even have a key sequence to toggle my proxy!

Desktop: Librewolf, Chromium as a fallback

Mobile: Vanadium on devices with GOS; adblocking via DNS. Cromite for my secondary phone and degoogled but not GOS tablet.

Zen (Firefox fork)

Firefox+uBO+BetterFox

Mobile: Ironfox

Search Engine: SearXNG (Disroot)

PC: Firefox, Librewolf and Tor

Search engine: I go back and forth between DuckDuckGo and Startpage

Firefox Focus and DDG on mobile. Qutebrowser and Librewolf on desktop.

Waterfox.
Sometimes dillo.

floorp on desktop. The developers are a team of Japanese students and it works well enough. I've had weird right click behavior after some of their many updates but it syncs with mozilla just fine.

Firefox/ sometimes chrome

Firefox, falkon, librewolf, tor.

99% zen, 1% helium on desktop/laptop.

99% firefox beta, 1% titanium on mobile.

Firefox on desktop as I haven't taken the time to migrate to a fork like Librewolf. Ironfox on mobile.

uBlock Origin on both, Rethink DNS on mobile as a local VPN style ad blocker across all apps.

Mullvad on my desktop. They don't have a mobile app available, unfortunately.

Duck duck go

Vivaldi and firefox

Opera on mobile and desktop

librewolf for desktop and ironfox for mobile!

Vivaldi

Desktop: qutebrowser/qutebrowser Mobile: uazo/cromite

Chrome

Fennec (with Betterfox and uBlock, etc.) and IronFox on mobile.

LibreWolf and Brave Origin as a backup on desktop pc.

Ecosia on the phone

Duckduckgo on the computer.