One can cite the differences between the sprites of male and female Pikachu in Diamond and Pearl as evidence that the one in Smash is indeed male--there is no indent at his tail's end.
In the games, 25% of wild Jigglypuff are male and 75% are female, so it's likely that Jigglypuff is female. The Jigglypuff in the Smash series is also alternately colored, with green eyes instead of blue.
I believe that male trainers always receive male starters (I always get male starters, anyway), but how RED got all three is open for interpretation. None of his Pokémon have visible gender differences as far as I know.
I don't care about Lucario.
-Toon Link
Fixed. :D