When I wear boxers, and they are short in the crotch, it hangs on the left leg side along with my balls. The same goes for boxer briefs.
If they are full fitted boxers, everything just hangs. But, if there is enough room to bounch about, then my dick tends to keep an on and off slight erection, and then it sort of sticks straight out, and a lot of times comes out of the front opening. I hate that when it happens! I have to find a place out of the eyes of others and poke it back inside.
If I wear briefs, it is usually a "pouch" type and it is either straight up or to the left.
If I don't wear underwear, and it is hanging a fairly good flaccid, and the pants are short crotch, then it usually hangs on the left leg side.
I prefer nothing, really, and then it just hangs!