Definitely Firefox. It's a more security browser for one. I know quite a few people who had very infected PCs and were about to throw them out for new ones because they could barely use them anymore. I told them to install Firefox and get rid of IE. Suddenly, none of the issues they had were happening anymore.

Also, there are cool features and plugins. https://addons.mozilla.org/en-US/firefox/

I have a problem with IE: It changes settings for itself that I need set differently to run other special software.

For the most part I use Firefox, but from time to time I'll also use Opera, Safari 3/win, Flock, and IE7.
Usually, I will only use IE6 for testing websites I buil, and the same for IE7.

I totally recommend that you download one of the browsers I listed above and stop using IE6 (except for testing if you are a developer or web designer). You'll enjoy the benefits of a faster and more secure web browser, that will load sites faster than IE6.

Yeah it's good for testing out your sites to make sure they look okay in IE. I use it for that also since most people still use IE just because they don't know better. But the percentages of people using Firefox is increasing a lot.

whether u like it or not, 80-85% of web visitors use IE . But from a developer point of view, most people prefer firefox becoz it supports various addons (which are of immense help)

That doesn't mean it's better or that you have to use it except for if you make websites and want to double-check that it looks okay in the browser.

Most people use IE because they don't know about Firefox. The people I have told to install Firefox have all stuck with it.

I say to the asker - just install it and if you don't like it, get rid of it. No hurt in trying it.

I like Firefox, It's original, and security purposes Firefox is safer or (often less exploited) than IE. Firefox in general functions pretty smoothly, in my own opinions has more capability than IE. However I will say this against Firefox. It has gotten a lot bigger than what it first originally was and it has added a few unnecessary features recently. The updates can be a little crazy with firefox (as there have been a lot of them (maybe it's just me who thinks so)), but that's a good thing. IE is really not impressive, like most microsoft products.

i think its good to use firefox bcoz it was easy to use and i prefer to use to use ie bcoz it is also easy to use but ie doest have tabs

I also think that Firefox is slightly faster to load and deliver pages. It's ten times faster to install. It also has tons of free addons. My favorite is Web Developer. It gives you a menu full of developer tools that allow you to use custom css pages, disable javascript and cookies on the fly, and tons of other handy stuff. But as a designer or developer, you are making a huge mistake if you don't test your pages in both browsers. While most of us use Firefox, most users of your site are still on IE because that's the browser that shipped with their dell or hp and they don't know what the hell a Firefox is.