It's between Opera and Firefox.
Opera 7.23 is good, better than Fire* .6 and .7
However, Firefox .8 is looking pretty nice, especially with the tabbrowser extensions. I checked out the current beta version of Opera, 7.50 something or other, and it's a piece of sh!t. So I am trying to transition to Firefox, I think it is headed in a better direction.
The only Opera feature I'm really going to miss is their numpad shortcut keys: The +/- keys zoom in and out (images and flash included, not just text), and numpad 1 and 2 cycle between tabs (whereas on Firefox you have to press Ctrl+Tab, and Ctrl+Shift+Tab.. ugh). Also on Opera you can click and drag an image on a website just a little bit and when you let go of the mouse, it loads that image by itself.
So, erm, right now Opera is the best pr0n browser and Firefox is better for just about everything else.