Amazon. I buy a lot there so it has my details already. Sometimes lets me short-circuit with "one-click" ordering. Saves my secondary addresses (I often buy things on behalf of family and have it shipped to them). Review system is easy. Usually my questions are already answered in the question area or reviews. Etc etc.<p>Basically I can do all of my comparison/shopping on Amazon and most of the time, I haven't missed out on anything.<p>The other online place I shop the most is Ebay. Unsurprising probably, but I'm shopping ebay for vintage objects (usually tools). Nobody else can compare in that category.