I quite like the Marcuse briefs. The ones with the 3D pouch show a good bulge, and some of those are unlined which gives extra definition to the bulge too.
eg
https://www.marcuse.com/swimwear/oas...yle-oasis_pink
Or if you really need to be on show
https://www.marcuse.com/swimwear/max...mo_neon_yellow