Safari - simply the fastest, cleanest on macOS.
Particularly like how it is not hogging memory and/or battery.
I also prefer Chrome on Windows (for work) and do find it amazing (particularly for dev-ing), but on mac for me is a bit cringey(how many years took them to do a x64bit version, wtf?). I guess extension hoarders might prefer that but I’m happy with the small, limited extensions available on Safari most of the time. The plugins I use are AdBlock (for some sites that abuse the limits of what I can put with in terms of advertisements) and AutoRefresh(big help for purchasing tickets or keeping a session in place) 
On Chrome I mostly use ReactJs & Redux debugging tools 
And personal worst is Internet Explorer from 6 to 9. Worst to provide support for. IE10 was a slight improvement. IE11 is kind of decent. Haven’t played with Edge much but hopefully keeps the general trend of improvement and not implementing standards ‘slightly differently for shits and giggles’.