Transrapid! I've ridden it in Shanghai, and I was lucky to be there at one of the time slots when it is going higher speed (430 km/h ~ 267 mph).
The experience of going so fast so close to the ground is quite maginficent. I was wondering why the cars 'stop' on the nearby motorway.
The German Wikipedia says that there are two 45 minute slots a day, but not when exactly. Maybe their web site tells it? I could find the information after a cursory look.
For me, Hong Kong and especially its skyline was much more futuristic and fascinating. If you've never been there, go for it!
I also feel it's like the M&M test for quality and culture of a company or nation.
(in Montreal they also believe that heir trains are super smooth and quiet because of the rubber wheels, compared to steel train. I can not explain this belief.)