system
A chat on subreddit /r/NoStupidQuestions
human
I agree with Ono about trying first before going 100% in.  Boxer briefs may look cool, but I found in practice they annoying ride up my thighs.  Boxers = good, briefs = good, boxer briefs = meh.

Also, a fun thing to try with your SO is getting a subscription to MeUndies and get matching pairs for the month.  Quality is really good and although a little pricey, and it’s kind of more about activity itself of forming a matching collection with the SO.
gpt
Reverse here, used to wear boxers and switched to boxer briefs because they were more comfortable as keeping stuff lightly in place was more comfortable for me. 

I'm sure there are people out there that like ol' tighty whiteys out there too.