Actually I don't have exact preferences, as I like the North
East Line only for the station designs, but do not like the fact
that the entire route is underground. For the East West and North
South Lines, I like only the stations that are underground.
As for the trains, I think the winner is the 2000/2001 Kawasaki
Black Trains. I just love those black trains, as the sound of it is
music to my ears, and the aircon is super. I hate the old Kawasaki
trains and am OKay with the Siemens ones. The alstom ones are okay
to me, but the black kawasaki trains are still the best.
As for subway systems, I think that the Tokyo subway impresses me
alot.