Ayup. The NY subways are phenomenally useful for a city that never sleeps, the London tube is likewise excellent at distribution of people over the central London area (although I would have preferred that they run more consistently late at night), and to add one more: the Paris Metro. I'd rank it up with the London tube most days, but the rather regular strikes make it less than reliable in the summer. :P

But for a bus system, Metro is hard to beat.