firefox or ?

Hi

Quick few choices are Firefox, Opera, Safari, Chrome and various other takes on Firefox like Flock etc all available here to download

Firefox and Opera are good and easy to install and configure, both give options to import your IE bookmarks, usage and preference in browsers is a personal thing so many like various different ones, I generally use IE as preference, but do have Firefox and Opera installed as at times I use them also.

Is there a reason for wanting to change?

I would install a few of them and see which one you like personally.