What lightofmind said.

Also, Firefox is open source, free, and the most secure browser on the market.

If you want the safest online experience, use Firefox.

It is also very easy to customize with themes and extensions and supports all the most common plugins (Flash, Java, Quicktime, etc.). And did I mention it's open source and free? And secure?

For more information, please check out: http://www.spreadfirefox.com

Also, the email client that was made by the same people, Thunderbird, is a very good open source, free, email client.