One of the reasons that FireFox has been my choice for the last two years is that I've already gone through the "unable to use secure sites" problems with Safari, and Safari is just boring. No extensibility. Not much innovation.
Western Union, my bank and other sites with a lot of security checks didn't like Safari for whatever reasons. Since FireFox is a well known, and supported, PC browser these sites were set up to work with it.
With FireFox, you get a hugh assortment of Themes (skins), and hundreds of extensions that have been built for or by windows users. They work with the Mac version also, because they are not using windows specific tools.
I've installed 8 or 10 Extensions for several reasons. McAfee SiteAdvisor lets me know a sites reputation for messing with machines with Trojans etc, which I also interpret as to their overall purpose. Adblock Plus blocks many of the most intrusive animated adds at MSN.com, Yahoo.com and many others. I just don't see the ads at all. ForecastFox adds the next week's weather to the status bar and is available on every web page. The search box lets me choose to search Google, Yahoo, Amazon, Answers.com, eBay, Wikipedia, IMDB, and even offers Microsloths "Windows Live" searches without going to these sites home page to run the search.
Oy-Oy is a great web site developers toolbar for search engine optimization. Web Developer is another toolbar that can be very useful. Xinha Here! allows an online store owner (like for Zen Cart) to insert html code into a web page while adding products to the store.
Everytime Firefox is updated (rather often in the last 4 months), security experts around the world have had a say on what exploits should be taken care of. When FireFox does update the program, it automatically checks all installed Extensions to see if they are compatible or downloads the updated extensions.
The only new, compelling feature I've seen Safari come out with in the last couple of years is it's ability to save a portion of a web page to be a Widget. I guess that's something, but not very useful for my purposes. Oh yeah, they added tabbed browsing, but FireFox had already had it for quite awhile. The FireFox developers don't have to worry about anything other than creating a great browser.
There have been problems with FireFox over the last couple of years, most notably, there were memory leak problems with early versions, but nothings perfect and the developers are very active. With FireFox you get the advantage of Windows and Linux programers developing these enhancements that also work with the Mac version, even if they don't care about the Mac.
