Firefox
From OLSEncyclopedia
Mozilla Firefox is a free and open-source web browser that runs on pretty much any operating system you can throw it at. It aims for full standards compliance, unlike Internet Explorer. Thus, most of the features of web design that people use and abuse (changing scrollbar colors, VBScript, ActiveX, nonstandard tags, etc.) won't work. Get used to it, it makes the web a lot safer place if everyone would just adhere to the standards instead of Microsoft's policy of "embrace and extend".
Firefox is easily extendable to add very many new features, such as an ad blocker, a more robust script blocker, integration with your music player, better tab/session management, and a LOT more.
Firefox also has a built-in search box, so there's no need to download and install search toolbar plugins. You can find search plugins for pretty much any site with a search function, and if there isn't one, they're easy enough to write that you could make one yourself. The search box also recognizes sites it can generate its own search plugin for, for instance, it offers me the ability to add a search for this very wiki.
Tabbed browsing means you can kiss having 7-8 (or even more) browser windows open at once goodbye. Tabs keep everything neatly organized into one window.
Firefox has a sidebar for the usual things like History, Bookmarks, etc. You can also bookmark a page and then tell it to open that bookmark in the sidebar, meaning sites like ImageShack can write a simple web page you can bookmark and set that option for to allow easy uploading of new images.
Firefox is a bit memory hungry, unfortunately, but there are some options tucked away that you can change to alleviate some but not all of the problem. Also, the major complaint of new Firefox users is that it takes forever to load pages, there are many settings hidden away that can be tweaked to virtually eliminate that problem. Utilize your Google-fu on the phrases "firefox memory usage tweaks" and "firefox speed tweaks" to find these settings and how to change them.
