Defog hasn't been used yet.
Defog was used in the Darkrai movie. When everyone found out that they were stuck in the town.
Strength was used by a Feraligatr in the sumo challenge on a Blastoise (Ep 196 Ring Masters.), but not actually to move boulders.
Apart from the others mentioned above, I don't know any others
Does Lapras carrying Ash and friends in the orange islands count as surf.
I think that they just tell the Pokemon to smash rocks, push boulders, ferry, dig, cut, etc.