Answers: Try them each, they're free. Firefox has more addons and can do more unique things, but it's also designed to be pretty lightweight so it doesn't have too many extra features to begin with. Firefox 3 does have a new URL bar that makes it immensely easy to find that website from two weeks ago where all you can remember is that one word in title, and a new way of storing previously viewed pages and bookmarks that makes searching your history a snap. Opera has always had a ton of great features, like their mouse gestures, that I can't live without today. Overall, the only negative thing I've noticed with the new Firefox is that its new zoom function, which now functions like Opera's zoom function by magnifying the entire site, causes unbearable lag on certain pages, for instance, Yahoo Answers, and sometimes on pages that have tons of flash and images. Otherwise, Firefox can probably do everything that Opera can do and more, although you'll have to find the plugins for those features and install them yourself.
I prefer Firefox over Opera, because less websites seem to render correctly in Opera. Until developers learn to support Opera, I won't be using it. It's too frustrating when so many sites don't load properly.
Who cares how great a browser is, if the websites I'm looking at don't support it!
Firefox is way better because its faster trust me i built my own computer and other peoples also i know when i say firefox is better
everything is better than Firefox 3 it crashes a lot
try Maxthon very fast and stable
definelty firefox waaaaay better believe me
firefox is good it you want to add plug ins and stuff
im using opera right now and i love it