Two rides after dark are sweet - Big Thunder and Expedition Everest.
Riding Big Thunder at night, at both WDW and Disneyland is an experience.
Before Disney nixed the extended evening magic hours at Animal Kingdom, Everest after dark was awesome. Inside of the mountain was much darker, and when you leave the station and round through the foliage before the big lift hill, is quite a rush.
Another ride at night would have to be Test Track and the rush of flying at 65 mph in the hot Orlando night. Test Track reminds me of some of the stronger roller coaster rushes I usually partake in at night at home in Ohio - Top Thrill Dragster, Maverick, Millennium Force, Magnum XL-200, Diamondback, Raptor, The Beast.
Lastly, the Jungle Cruise, both at WDW and Disneyland, are quite special after the goes down. The darkness adds to the mystery of the cruise. Kungaloosh!