Chrome for mac – with extensions =)
Ive been using chrome for mac dev build for a while now, its stable enough, and has themes and extensions.
it doesnt look as good as the beta for the mac, which integrates nicely with the snow leopard UI, but there is a theme available that will fix that.
as for extensions, I use AdBlock to block ads.
I use the RSS extension by google to add a subscribe to rss feeds button (which will let you subscribe to the feed using google reader =)
I use Xmarks to manage my bookmarks (I use it because I can have all my bookmarks synced on all my browsers on all my machines – the google bookmarks sync isnt ready for that yet)
I still use firefox, because it has firebug (I use it for web development, and I use it for soundcloud, because it doesnt work in chrome =| ) but im finding myself using chrome as my main browser, purely because of the speed of the beast. hopefully it will stay lean.