I've been an Opera fan for quite a while, but recently i've slipped towards Firefox (even if 1.0.6 keeps crashing on me). Out of the box Opera is a fair bit better - in fact, Firefox comes behind Safari too - but i'd be hard pressed to do without some of the Firefox extensions. The brilliant Adblock and NoScript in particular, but CustomiseGoogle, SessionSaver and PasswordMaker too ... and I keep finding more