In all honesty, it depends on what you do in your browser.
In my line of work I use pretty much every browser to make sure **** is cross-browser compatible, and I haven't noticed anything about any browser that makes it stand so far out against any of the others. I use Firefox primarily because I have a good number of addons that I use regularly, but from what I hear, Chrome has pretty much the same stuff available if I went to the trouble to find them.
Chrome in general, looks cleaner, it's a very minimalistic approach to a browser (as is most of google software), which is a definite plus, I hate having loads of **** camping at the top of my browser but some people love that. It also has the google search bar built into the address bar, unlike firefox which you have to tab to get to.
Also agreed that IE9 is supposedly the ****, although it is in beta so expect there might be a couple bugs here and there. Also note that none of the current browsers fully support HTML5 so if that's your thing, or you're keen to try out some of the funky HTML5 shiz that's available, you'll probably need a couple of browsers to test with as they all seem to support a handful of functions that the other browsers have chosen not to support. Go figure.
Also there's something about the way FF encodes videos that's different to every other browser cause FF's philosophy on software is open source stuff and the standard (H264 if I'm correct) is not open so they use some funky encoding. I think it's pretty irrelevant to most people and I'm sure there's more to it than the sentence above, but just a fun fact I guess...