For freebie figures, there are:
GUY for The GIRL
Lee, the Male Sara
MayaDude and Guyadude for MayaDoll
Aiko3 Male
Stephanie Boy ( Japanese morph version, I think for S1, not Sp3)
Kururu Boy for Kururu
Gemma for P4 Male
HER-Male and HER-man for H.E.R.
( think there is also a He for the She figure !!!)
Pichi for the NEA P4 Female morph

Miki2 Finn ( not free, and makes your Miki2 into a male)
BJD Boy for BJD Doll (which isn't free)
Anime Boy morphs for AnimeDoll ( also not free)

I am certain I have more transgendered figures in my runtimes, but these are the ones I can think of right now.

Eternal Hobbyist