Hong Kong Very shiny, clean and efficient subway system. It's remarkably easy to slide off the metal seats if you're not paying attention to corners.
Warsaw has a single line subway system. Bugger all use. The city council chose to have a
Palace of Culture from Moscow instead when offerered a choice between that and a decent metro system.
London Underground is hellish. Useful, but foul. One of the oldest, one of the most run-down and underfunded in the world. But it's still my favourite zoo.
Paris is a confusing subway system, but, at least the old
art nouveau station entrances are pretty. The tunnels are spooky.
the
New York Subway is filled with stories.