Whoever designed the KCR stock refurbishment should be shot. The seats are not sculpted like the MTR trains which makes it extremely unpleasant to sit on.
Hong Kong MTR:
One of the most reliable, clean and efficient metro systems in the world.
Cleanliness and modernity however comes with a lack of character. This wouldn't matter for ordinary people but the MTR is rather boring from a transport enthusiast's point of view due to the homogenous interior.
Japan Railways East:
My fav rail system is actually JR East in Tokyo! It has a lot of track mileage and the map below only becomes readable at 3300x wide!
There is a large variety of rolling stock and interiors although the new stock has been using standardised fittings for the last 15 years. JR is immaculately clean and always runs on time (unless someone jumps into a train). Although I rate the MTR higher objectively (station facilities, modern looks and such), I have a liking for JR East as it is a really fun system for the enthusiast. The railtrack is in mint condition, allowing standard width trains on
narrow gauge go around turns at stupidly fast speeds.
A JR East E231 electric train on the Yamanote line. This train maintains a high rate of acceleration up to 80km/h and beyond.
Hong Kong busses:
Hong Kong is a bus spotter's paradise with plenty of variety and density of busses. The bus companies like to mess around with the chassis/bodywork/engine/transmission combinations which adds even more variety. These days, the bus density in Hong Kong's too high for the amount of roads we have, thus creating a lot of bus-jams. Still this is my fav bus system as it is relatively clean and the drivers look more focussed than those in the UK in general.