Almost always Safari, mainly because it seems to have settled into a standard interface... which probably means that there will be major changes after EC comes out!
I also used a "Poodle-proof version of Chrome during the first part of the year. I had to find a replacement for Speed Download a few weeks ago, so I ended up updating Opera, Chrome, and FF. That was the first time running any of them for several months! Habits are hard to break, but I also try to use most of the apps my wife does, so I have a better chance of finding a problem she might have...after 50 years, the fact that 'if momma ain't happy...'