i have always stuck with FF for firebug and because of how much i can customize every single aspect to my needs. i think opera fits the bill as well, but something about its UI doesn't work for me. ff is plenty fast and i dont need to deal with untweakable interface decisions as i do in chrome. i have said for a long time that i would give chrome another try when they give me an about:config equivalent and a fully customizable ui, but that's not in the cards.