I wasnt really unhappy with IE, but was never a supporter of any particular browser either and used to think of it as Open the browser, surf the site u want, close the browser kinda thing. But when I tried Firefox on someones suggestion, I got introduced to some features which I found were really useful.
First thing is, its actually a little lighter on the system, its got inbuilt search bar with options to select your search engine. Not just google. You can add to this list too. There are a host of extensions or plugins available ranging from small but usefull type to quite elaborate types. A few of these which I use regularly are
Autocopy - Copies the selected text automatically (very liek UNIX prompts which I am used too)
Scarpbook - Useful when u dont want to bookmark the site and dont want to save the
whole page. It saves just the selected text to your scrapbook, which can be then grouped, managed, rearranged , exported etc.
Minimizeto tray (third party plugin) - minimizes firefox to system try, useful to keep your toolbar clean. RSS Tool - News updates and tickers which you can customise according to your needs and many more such plugins.
And I havent talked about the themes (skins) yet ! those are like really cool. Although there is a bit of a problem with the themes. Some of the themes dont display the scrollbar and status bar properly when the window is resized or not mazimum size.
Neways ... The bottomline is if you wanna try something new and fresh in internet browsing try firefox.