if you're worried about being safe on the net, use Comodo Browsers (Dragon/IceDragon).
Dragon is based off Chromium, but is actually given security to the fullest. (Chrome/Chromium security is a joke and is not to be trusted)
IceDragon is based off FireFox, but has much greater security and speed. (FF has better security than Chrome, but I think IE now beats it)
both Dragon and IceDragon offer the same security benefits, use what you like.
as a user for almost 5 months now, I can garuntee this browser works perfectly when it comes to protecting your compy

(though I've disabled all cookies and JS (excluding my trusted sites), and installed about 5 extensions for protection)
No modern popular browser can even come close to the browser security of Comodo browsers, so if you want to stay safe, I recommend using them

@Avast guys:
if this counts as advertizing, I'm sorry, there isn't much light that comes out of software now-a-days.
I'm not here to mislead people into getting crappy freeware... I've had my compy destroyed enough times thank you.
I only recommend the good stuff that actually works and can be trusted.
there's also the option of you guys catching up to Comodo and offering a full free suite of products that actually work as they're supposed to.
(the only difference is the paid versions of those products are much more convenient and easier to set up)