I use Opera 9.62 .
Of course I may change it for the latest one but do not.
It is not too comfortable but fast and has a lot of features. I had found one site (on Dec. 2010.) which did not support Opera because the javascript codes of the site. I do not like such sites, so not problem. Maxthon is also has good enough speed.
I tested several older and latest browsers (but did not test Chrome, Safari) for my php/html scripts :
SUSE Linux 9.0 (only for html forms): Amaya, Galeon, Mozilla, Opera, Epiphany, Konqueror
for full test on XP (XAMPP) : Avant Browser 10.2, Mozilla 1.5, Opera 7.0, ~ 8.0.2, ~ 9.62, Netscape 7.0, Maxthon 1.6.7,
Firefox 3.0.3, Seamonkey 2.0.11, IE 6.0, Flock 2.5.2
Maybe the best for show a pretty site design is Firefox. And obviously one of the worsts for this is Opera.
(The pages in the latest Konqueror versions /Linux/ also look good.)
But it is not important for me.
For example on my hobby site to watch the pages I recommend these browsers :
Maxthon 1.6.7 or later, IE6.0 or later, Opera 9.62 or later
Because the most important is for me about my pages is the page zoom.