Firefox mainly, but also Edge which i like too
Chrome and Opera have merits too, I'll use any but firefox is just about my favoured browser
Back in the 'browser wars' days it was mainly Netscape v IE and following the whole IE monopoly accusation (which still seems strange to me in some ways) it was on trend to be against Microsoft in every aspect and become a somewhat unquestioning advocate of anything open source or anything non microsoft .
The former over sold the benefits and over promised on timescales and capabilities (just read old advocacy forums from around 2000) but those benefits slowly and surely caught up, even on the desktop PC a linux distribution such as ubuntu or mint is really good these days
Well, the latter field was dominated by Apple, who have become specialists at raising barriers to entry for their stuff, marketing it effectively and charging accordingly. It amazes me how many Apple fans still see themselves as somehow counter culture or cool, it is the very embodiment of mainstream capitalist consumerism
Meanwhile the relatively shrunken but still powerful MS has become more innovative and interesting in my opinion
However I still use Chrome for the extensions, and also because I truse Google more
I'm not sure I'd trust google more than microsoft these days!