Well, I like FireFox, though I only use it when developing. I like the JavaScript console.

Though what I don't like it is the integration, or lack there of, with Windows.

I'm used to just puting in h:\ into the address bar and well, seeing the contents of the h: network drive.

It may seem trival but FireFox really doesn't have that many advantages over IE so this gives IE the leg up in my case.