I just use Nitro cleaner. There are many brands out there, all do a good job. Just make sure that you don't give your servos and electronics a soak while cleaning. Also good at getting the gunk off the inside of the body, but after a while the paint seems to thin out so a package of baby wipes comes in handy for the body. Everyonce in a while, take the engine out for a good cleaning, but while the engine is still in, make sure to keep up on the build up around the carb. The stuff is also good at cleaning out the foam filter. Just remember to reoil the foam.
Every so often, I completely disassemble the car just to make sure everything can get cleaned while doing maintainance.