Looks like Chrome would be the best choice. Take a look at this Pwn2Own competition, its a zero day attack on browsers.I was very surprised by the results, other than Safari being the first to go down.
People always think that Macs are safer, which is completely untrue, its just that the hackers go were the money is and there are more PC's. This means Mac's are attacked less and the security flaws are not found.
The other top three browsers were taken out a little while after that by one guy and an exploit of his own making.
They said they found a security flaw in chrome, but couldnt get past the sandbox.
Miller also told reporters that he targeted Safari on Mac OS X because he believes that it is the easiest to exploit. Windows, on the other hand, he claims is tougher because of its address randomization feature and other security measures. As for Chrome, he says that he has identified a security bug in Google's browser but has been unable to exploit it because the browser's sandboxing feature and the operating system's security measures together pose a formidable challenge.
http://arstechnica.com/security/news/2009/03/chrome-is-the-only-browser-left-standing-in-pwn2own-contest.ars
JoanRC, I'm with ya on Linux and have tried to migrate to several times, I even have several partitions setup to install linux again. I did this whenever I got windows 7.
i've just been waiting for them add support for my motherboard and processor and I'm ready to go. It's super annoying to to enter on every install pc=nomsi, half the time I still have trouble installing my video card.
The benefits though, well worth it. games and everything are so fast!