I ran some checks on my database (it has the data of exactly which pokemon learn which moves so I can get stats from it) and found that there are 12 moves learnable by 481 pokemon, and 2 by 480 pokemon (next down is only 427 pokemon).
Swagger, Natural Gift, Secret Power, Facade, Double Team, Substitute, Sleep Talk, Toxic, Endure, Hidden Power, Frustration, Return
The pokemon that can't learn those moves are:
Caterpie, Metapod, Weedle, Kakuna, Magikarp, Ditto, Unown, Wobbuffet, Smeargle, Wurmple, Silcoon, Cascoon, Wynaut, Beldum, Kricketot, Burmy, Combee
(And Regigigas can't learn the other two)