I primarily use Chrome 'cause it's faster and I find it has a much simpler interface than IE. I got sick and tired of IE crashing all the time about 4 or 5 months ago, so I just downloaded Chrome and haven't had nearly as many problems. I like the customized skins as well, but just cause I'm all artistic like that I guess...
I also have Safari installed on my computer, but I have never really used it.