For a long time Firefox has been my browser on Windows. But on Macs I have stuck with Safari. On my Mac I just liked it better, even though Firefox had some things I missed in Safari. Some of that probably just had to do with the skin and it "looking right". (And yes, I know I could have skinned it or tried Camino or whatnot.) But in any case, with Firefox 3 being released in final form yesterday, I went ahead and tried it again. Within a few minutes I had decided to change default browsers. It is quite good. If you haven't yet, head on over to Firefox's site to download it. Very worth it.
There are still a few things I like better in Safari, like the form button shapes, the find function, and resizable text boxes. Overall though, Firefox just has enough little things to make it worth it. (Better URL autocomplete, selectable search box, extensions, etc.)
I'll give Safari another shot next time they push a major update to it. Snow Leopard maybe?
Or maybe something will really frustrate me about Firefox in the next few days and I'll go back early. But right now I'm doubting that.