Two more challenges (hope it's not already done) :
Crazy 18 - 100% (Hard, but possible)
Crazy 19 - 100% (Once you find the way, it's a piece of cake)
Both were mentioned in the old thread, but still good. There's also the ceiling route for Crazy 19, but I don't know if it's possible to get 100% this way. 18 would have a ceiling route if there was more time...