I have IE, Firefox, Chrome, and Safari all on my machine. I think I like Chrome the best. What do you prefer?

IE is a system requirement of Windows, but I never use it. Firefox has been good to me over the last couple of years. The level of control you can have over it is very good and there are plenty of fine quality add-ons such as Flash Block, Foxy Spider, DownThemAll and so on. I don't know why anyone would use IE and I haven't been persuaded to switch to anything produced by Google (who I don't like).

Firefox definitely. Been using it since version 0.9. It has the most useful add-ons when it comes to surfing porn sites. There's also the pinned thread "Firefox - the only way to surf porn" right here in this section that lists many of those good add-ons.

Definitely Opera. I never understood why it's not more popular (especially for porn browsing...) ;)
There are a few inconveniences how some pages are displayed (but this is improving on more recent versions) but the advantages are just to many!
My favorite is the possibility to download a whole gallery at once via the "links" panel :)
And the best is that it all comes with the browser and does not need to have loads of add ons (and still is more performant than e.g. Firefox)

I like the IE9 best. Extremely quick...