Thanks Dan for giving me this idea for a great thread. My favourite has to be Prague - it is stunning and wonderfully clean and quick. An absolute pleasure to be mugged on there, seriously.
If you haven't travelled on the Moscow metro, get yourself on it right away. Stunning station and connecting walkway decoration and now featuring western as well as Cyrillic alphabet signage so you really have no reason to get lost, except if you've decided to get off to follow one of the many stunners you see on board. Orgasmic.
Glasgow's use to be all right then some bright spark had the idea of wasting loads of money ruining it. #bringbackthebrown
Terrible decor Overcrowded Overpriced Smells Crap trains Old unmodified unmodernised stations Full of southerners
You're thinking of Paris. Now that really is a ****hole. Plus there is a fair chance you will be pick pocketed by one of the smelly locals.
I agree it's overpriced. Howevber, most of it has been modernised - the majority of trains are as good as anywhere else, the stations have all either been refurbished or are being refurbished and there's not much you can do about overcrowding in one of the 10 busiest cities in the world. For a network its size it is far from awful.
Paris underground is a great place to go if you want to get brutally raped and beaten up. London Underground is fine and works well most days, can't wait for it to be 24h on weekends next year