Almost always at the gym, as I've been doing for the past 40 yrs. Until recently, most gyms had open shower rooms, no stalls or curtains, and it was always a pleasure to see other guys naked, even if only for the eye-candy. I've always been a nudist, so being seen by others nude is nothing to me.
Lately, tho, gyms now have stalls and curtains, which certainly curtail the views, unfortunately.
The other reasons I prefer showering at the gym: keeps my day clothes clean(er); can take as long a shower as I want; I shave my crotch, balls and ass there more easily than at home.
:lolp: