Looking for a new browser

Hi /comp/
I've been using Avant browser for a long time now, which is basically a shell for IE, and my friends tell me I shouldn't use IE for some reason, despite not having a single problem with it -_-
Anyway, which browser would you recommend, if I mainly browse forums and 4chan and check emails? I've tossed it up between Firefox and Opera, which one do you guys use and what are the pros and cons of each?
Thanks :)

>>9-11
Up-to-date stable versions of Firefox include that. (You might have to set a preference, or not, as I have those settings commented out in my user.js?)

Seriously, you can't compare Opera to obviously outdated versions of Firefox like 1.5 or 2.0.