I can’t give a perfect answer because everyone likes to surf the Internet in their own way. So somethings that matter to me (add-ons and plug-ins) may not matter to you. But one thing that should matter to all of us is security. Another that should be important but the average public does not know about is web standards. Microsoft is trying to be better at this but is still falling short, but many of the other browsers follow the standards.

I am a huge Firefox fan, and I use the browser on my home computer, although I use a combination of IE, Firefox and Opera, (for testing purposes). Each browser has its own strengths and weaknesses. However, I have found Firefox to be a strong contender for the best all-around web browser.

Firefox 3 

(download)

• Strength – Thousands of add-ons, themes and the community of developers / designers behind it.
• Performance – It employs Gecko 1.9 to enhance the existing layout engine. It passes Acid2 test and gets better results on the Acid3 test compared to Firefox 2. Basically, it means that Firefox 3 is more CSS and javascript friendly.
• Security – Does not allow a website to download onto, install onto, or execute code on a user’s computer without the user’s agreement.
• Usability – The download manager and bookmark storing system are redesigned, and are easy to use. Also, it separates the themes for Mac, Linux and Windows, and that means users will have a more native look and feel on different operation systems.

Opera 9.6 

(download)

• Strength – Fast and small, standards-compliant, and available for many operating systems.
• Performance – Provides textual content before ANY other browser, and noticeably faster than IE for total page loading time. Opera’s cache (especially the back/forward performance ) is simply faster than any other browser.
• Security – Opera has a very good reputation in the security community for always fixing any possible security issues as soon as possible
• Usability – The first browser to introduce mouse-gestures. The whole User Interface, including all the menus, keyboard commands, mouse gestures, tool bars, and even individual buttons are extensively and easily customizable, using a user-friendly GUI driven interface for most features

Safari 4 Beta 

(download)

• Strength – It is the default browser in Mac, and it has an elegant interface.
• Performance – It has support for CSS Web fonts and animations and improves support for SVG and HTML 5 media.
• Security – Uses robust encryption to ensure that your private information stays private
• Usability – As-you-type text search, Quartz-style font-smoothing

Google Chrome 

(download)

• Strength - It is fast, secure and multi-processing structured.
• Performance – Chrome uses V8 JavaScript engine to generate javascript code dynamically and hide class transitions automatically. It also uses multi-processing architecture, which allows the browser to shut down a single Tab or a plugin wherever problem occurs but to keep the whole browser alive.
• Security – Chrome warns users when they attempt to visit a harmful website based on google’s phishing and malware blacklists, which is being updated periodically.
• Usability – The Tabs are placed at the top of the window in order to make the navigation faster and smoother. Additionally, Chrome displays 9 most visited web sites and sites most often searched on the home page.

Internet Explorer 8 Beta 

(download)

• Strength – It is the default browser in Windows
• Performance – Accelerators, Automatic Crash Recovery
• Security – InPrivate, allows IE8 not to save searching and browsing history, cookies and form data. In another words, it clears the browser cache by default.
• Usability – Search Suggestions, Web Slices, Tab Color Grouping

Acid3 Scores:

Safari 4: 100/100
Chrome: 74/100
FF3: 71/100
Opera: 60/100
IE 8: 17/100