Guys, definitely, without a doubt, look the best in old school traditional white briefs. Summer/Spring, nice tan, tighty whities. They just work, and work really well. It’s a very masculine, athletic, locker room look. Also, can be boyish too depending on baby face and height. Different on each guy.
Now, if over weight, or a bit too gutty, then boxer briefs are a much better choice. Unfortunately, tighty whities are very unforgiving and, definitely, have to be, at least somewhat in-shape, with thinner waist.
Also, not the full rise underwear you wore at 7. LOW-RISE or MID-RISE, more expensive tighty whities. Tommy Hilfiger, Hugo Boss, the more designer styles look just amazing on guys.
if in an open changing area, locker room, showers, I want to see guys in tighty whities underwear.