Beautiful URL, what's better?

It has long been tormented by the question of how best to call directories:
site / user s / or site / user /?
Because on the one hand, the list of all users, photos, files, etc. is / users /, and on the other, if you open a specific object, then / users / vasya / is not as beautiful as / user / vasya /

The same for / photo (s) /, / group (s) /, / file (s) /