If you really want safe browsing, free from malware, use Linux.
But for daily browsing and keeping in touch with folk Linux is way less hassle and maintenance free.
Windows security has been decent since Win2K/XP and has been very good since Vista / 7.
Consider my setup: Software Restriction Policy, UAC, standard user, Firefox running with low integrity and as different standard user.
If malware comes in via the browser :
It can't write to any medium integrity directory.
If it somehow manages to break out of the low integrity sandbox, it can't write to my user profile because Firefox is running as a different user.
It can't execute because, for a standard user, SRP disallows file execution from directories other than C:\Program Files or C:\Windows
It can't write to C:\Program Files or C:\Windows because of the combination of UAC and standard user.
That leaves us with phishing / Java / Javascript / IFRAME type attacks... which Linux is also vulnerable to?
If malware manages to gain access to my user profile, I'll be impressed. If it manages to write to ( and subsequently execute from ) either of the above two directories, I'll bow down before it and admit defeat.
