Safari. But when I had a PC (just a few weeks ago; well, technically I still have it), Firefox.
Does Safari beach ball on you often? I used to try Safari every time it hand an update. But it would freeze on me so often, never for very long just quick beach ball during a page load, that I got tired of it. Whenever I say that people jump on me and declare I'm wrong. They usually tell me there's something wrong with my set up or I have a bad extension or something. I've tried Safari on everyone of my family members computers, and while not always freezey (new word!), it's usually a little annoying and I've had the same experience with Macs at Apple Stores. But I also have had fast and great Safari experiences with Macs at school, my personal computer, and at the Apple Store.
I think the issue may be related to my slower Internet connection, but I don't think the application should beach ball even if it's still loading a page.