Best software by experience

Hello, friends!

After my experience, commercial software is not as good as free open source software regarding usability, stability, compatibility, network accessibility and security. Therefore, if you have bad experience with other software try my suggestions. Every program that is listed here has been used by myself successfully for at least 1 year and is still in my use.

The best web browser: Firefox 3 if Internet Explorer does not satisfy you
The best anti-virus software: Avira AntiVir provides more security for your Windows
The best office suite: OpenOffice.org if Microsoft Office is not good enough for your needs
The best operating system: openSUSE if Windows is not good enough for your needs
Best instant messaging Skype with VoIP (Internet telephony)