Aaron Taylor-Johnson is huge! I was so surprised with the size! But he was soft, of course. Two long frontal nude scenes in A Million Little Pieces.
Ewan McGregor is so big too! He is naked everywhere but I think that maybe his 2 best naked movies are: The Pillow Book (1996) and Young Adam (2003). No erection again.
Luis Alberti is huge and shows his erection in Eisenstein in Guanajuato (2015), Peter Greenaway doing his magic again!
Elis Gardiole with his 10 minutes nude scene (with erection) in À genoux les gars (2018) must be at least in a TOP 5.
But who is the biggest one you have ever seen?