Well, I've been using Opera in OS9 and have liked it a lot. It's fast. It's missing some of the nice things in IE that I've grown to love (pop up windows behind the main window, that tabs on the left, etc...) but the Google bar almost makes up for that!
I downloaded iCab twice but it was corrupted each time.
I tried Omniweb for a while. I do like it. It's incredibly fast. Unfortunately, it has that stupid slider-panel for bookmarks. I really dislike that interface widget in OSX.
That said, IE5 for OSX just isn't working for me, so it looks like Opera is the winner for now...