Ya basically the one that works on the most sites while also not being a PITA.
Being older than the internet and having used mosaic, Netscape navigator, IE, Firefox, Chrome, several short lived mobile browsers and tried Opera a few times. Can’t say I have a favourite as any browser I like that becomes popular also tends to become bloated and slow over time.
I have been using Vivaldi for about half a year and so far it is working well for me. Originally moved to it due to it's privacy features, but finding other areas quite useful too such as workspaces
I use Vivaldi as well but every time I update it I need to change one of it's internal JS files to remove one UI restriction that annoys me: I use two vertical tab bars, one for showing all the tab groups and another for showing the tabs inside the selected group. For some reason Vivaldi limits the width of the two sidebar (combined) to 330px, which is too small for my tastes.
Started using Zen browser recently and it's not bad! Basically Firefox but more stylish and more privacy. It syncs with my Mozilla/Firefox account so on mobile I just use Firefox.
The short answer: NetSurf, because it is the only contemporary web browser that also works under Plan 9, is extremely resource-efficient and is not based on one of the big (= commercial) browser engines.
The long answer: It depends. I like to use eww to test the accessibility of a website, but since Mozilla destroyed everything I liked about Firefox in November 2017, I've been using Vivaldi as my main browser. Although Vivaldi is based on Chromium, it is quite privacy-friendly, performant and extremely customisable. Unfortunately, some websites do not work very well with NetSurf. (I like to report this as a bug to the website operator. It is fatal that everyone always assumes that everyone wants to load and execute hundreds of KiB of JavaScript).
Upvoted for NetSurf. I wrote the Amiga frontend for it, and as such it's my favourite browser on that platform (OS4 anyway - the OS3 build is very unstable)
Pale Moon, originally forked from Firefox many years ago (although the codebases have diverged so far that most Firefox patches no longer apply). Still xul, still supports Firefox extensions from back in the day as well as extensions purpose-written for it. On the downside, it occasionally isn't compatible with the latest bleeding-edge nonstandard Javascript features—I keep Vivaldi around for the extremely rare occasion when something goes wrong with a site that I absolutely must visit for some reason (I think I've needed it twice in the past five years).
I love Firefox because with about:config and User css you can configure it just like you want it. Also Falkon because you get a fully featured browser that runs decently on older hardware
The overhead and performance hit aren't worth it for me in general since these browsers are set up to enforce secure connections as long as you don't override it. And I don't have to worry about government level website filtering. I do see the value in tunnels for stopping the ISPs from tracking and selling the list of sites you connect to, but I'd rather set up my own proxy for that if I felt it was worth it. It's easy enough to set up a web proxy on a small, cheap, remote VPS or pay for a trustworthy service with no logging so the ISP would just see that connection and it would be way faster. I don't see much value in using a Tor browser otherwise anymore now that HTTPS is ubiquitous and secure DNS exists, unless you want to access things not on the public web.
Sadly not available on Linux, but Arc has the best tab management paradigm of any browser I’ve tried, by far. Pinned tabs with folders, workspaces, and home urls goes hard.
On the other end of the spectrum, I’m very fond of qtbrowser. If you want a keyboard centered workflow it’s hard to beat.
Mobile: Brave. The reason I'm using Brave is Firefox-based browsers on Android lack Site Isolation. Who protects you against a malicious site performing a Spectre-like attack to gain access to the memory of another website you have open. Chromium-based browsers like Brave do have this.
Gonna go ahead and be downvote sponge here: Brave. Its privacy features and integrated Adblock have no peer that I’ve found yet, and easy bookmark/history syncing across multiple devices.
Yeah the CEO is a POS. Find me a tech CEO that’s not, besides Meredith Whitaker.
Honestly, I don't get the hate for Brendan Eich, he created JavaScript (awkward design, but it was hugely successful) and co-founded Mozilla, so I think he was a fantastic influence for the open web until someone decided to make a big deal about his private donations. To be clear, I disagree with his political positions, but I don't think they should have any bearing on his suitability as a leader at Mozilla, and I think Mozilla would be in a much better place had he stayed on as CEO. I like the initiative of Brave Search, and I think, in general, Brave is doing a lot of interesting things.
That said, I use Firefox because I believe strongly in open web standards, and Mozilla is the biggest competitor to Chromium's rendering and JavaScript engine. I use Brave as a backup browser (i.e. testing for Chromium browsers, random pages that don't work on FF, etc), but I won't daily drive it while a credible alternative to Chromium's rendering engine exists. I'm also disappointed at some of the choices they've made (e.g. the BAT thing should've been a way to pay to remove ads, not a way for users to get some kind of profit; I'd love to be able to pay a few cents here and there for ad-free content I like).