Correction: Firefox version 0.9.1 is the most current release.
Check it out: How-To
Fire Internet Explorer and Outlook Express With Mozilla Alternatives
Firefox is a free open source web browser I think you'll like. Currently in release 9.1. Tabbed browsing, popup blocking, it offers to import your IE bookmarks when you install it. Not emntioned in the article is that you can easily download "extensions" that add functionality. Just pick the ones you want. For example, I have an extension that lets me select any word, right-click, and look up the word in online dictionaries. Another called "BugMeNot" that lets me right-click on pages that require registration, such as the NYT, and it'll show me a username and password to use for most sites. Another neat extension lets me select an url, then paste it here with the UBBC code inserted around it to either make it a clickable url, or to make it a clickable url that I can put the title of the article into, if you know what I mean. It'll also make your normal bold, italics, etc code for you. Another extension lets you click on a long url and automatically generate a short url for it from Tinyurl. You get the idea. There are quite a few extensions available. Also downloable themes if you want to improve the looks of the browser.
Thunderbird is a free open source email client in the 0.7.1 release I believe, and it's pretty sharp because it has built-in spam protection. You "train" the spamfilter to recognize what is and is not spam, and after a week or two, when you get the spam filter set up properly, you tell the filter to automatically put all future incoming spam into a junk filter, or delete it off the server. Pretty neat.