There are many people that think Firefox is the perfect browser. This site explains some of the Firefox myths and gives answers, mostly from official sources. While some claims are inaccurate or biased (like "The security of any browser is irrelevant to if it is part of the operating system", "ActiveX gets a bad rap as the cause of all of Internet Explorer's security woes. But it's just not so"), I think it's an interesting read.
Firefox has lower system requirements than Internet Explorer 6 - false
Firefox is the fastest web browser - false
Firefox is the most secure web browser - false
Firefox's memory leak is a bug - false
Also see:
Reduce memory usage in Firefox
Firefox 2.0 Beta 1 available
10 features you'll only find in Opera