I will always have a special place in my heart for Toronto's system, as it was the first one I rode and it started the addiction. It has a great integration of subway to tram and bus, with intermodal stations all over the system. The stations are not that interesting, but they got good artists to do murals.

Montreal's stations can be a bit run-down (or at least dated), but it's an even more efficient system in a city that doesn't normally do thing efficiently. There are no stations above ground, which is vital for a city that gets a lot of snow. Stations are well-enclosed so you never feel stifled or frozen. (I hated that about the otherwise wonderful Lille system: the stations were cold but the trains had no ventilation so you froze-sweated-froze. There's no worse feeling than drippy sweat freezing into your clothing as you return to the surface.)

One of my favorite stations in the world is Lionel-Groulx in Montreal. It's a transfer station. Instead of putting one line upstairs and another downstairs, they put all the "eastbound" and "westbound" trains on the same level. Thus the typical commuter crosses the platform to change to a different trunk line in the same direction, rather than jamming the escalators. Too bad the station is named for an anti-Semitic priest.

Philadelphia has one of the worst systems. It's the most bureaucratic transit process I've ever seen. Where is the station entrance? Okay, now where are the signs to tell me I'm on the right path to the turnstiles? When last I visited in 2006, I had to deal with two people at different booths in the same station to get a two-day pass (which was made from paper-towel with a punch hole and a decal placed over it). They had stations with tracks buried in dirt.

London is fascinating for its layers of cruft. You can see the priorities over time by seeing what gets modernized and what is just good enough. Compare the very modern stations on some of the oldest railroad viaducts in the world in the up-and-coming Hackney area along what is now the London Overground. They're bright and inviting for a place people didn't want to be caught dead thirty years ago. Meanwhile the staid and wealthy Russell Square still has two deep elevators (much like Clark Street station in Brooklyn Heights) that still do not lead to a handicapped-accessible platform. If you have luggage, get off at King's Cross and walk.

New York City and Boston have ancient signal equipment. Boston has ancient equipment in general, with the section of the green line along Boylston Street hosting track that expects a small tram at 6 MPH instead of articulated beasts that would rather go 50. However Boston's system has so much history to it, and its cantankerous squeaks and sloppiness suit the city. I miss ringing the tubular bells with the swinging pendula hammers at Kendall, almost as much as I miss the trail of bronze gloves from the street to the deep tracks at Porter. I even miss the Brutalist stations in Malden on the northern end of the Orange Line.

I still haven't been on any German or Russian systems. I want to visit Berlin, the system that got split then put back together. I love Brussels, even though it's a beat-up set of strangely related metro and tram lines. It's hard to resist getting every type of interchange along with half a kilometer of the best graffiti on Earth (and a Chinese pagoda from the 1935 World's Fair across from a dentist's shop).