In my room at present: Desktop, 2x monitors, speakers (well, amplifier unit but same purpose), guitar amp, 2x vivarium UV starters, 2x vivarium heat lamp, alarm clock. That's stuff that is plugged in constantly, there's various chargers plugged in also but as they're not in constant use they could rotate in a single socket. In certain circumstances I have used up to 2 guitar pedals at once (own 4 but never use them all) .. so I shall say my power needs go to around 12.
Currently have 6 outlets in my room, but due to extensions/multiplugs I have 21 available.