I use 3 mainly. Vivaldi is my default, but I also use Firefox and Chrome.
firefox because I've done that for over 10 years.
Chrome on phone
Internet explorer is the best
opera / tor when sth is blocked on opera / when I need battery life on laptop safari xD
mostly firefox but i have chrome also on pc.
chrome on mobile
Chrome. At work I'm forced to use IE cause the applications are build for IE :'(