Yeah both the monitors and computers will consume a bit. Even a modern PC when turned off is in a type of deep sleep mode, for stuff like wake on LAN.
The chargers will hardly even register anything, except maybe in some rare case where its a special one that is doing some sort of passive listening (like the PC's)
A funny culprit I found during my own investigation was the GFCI bathroom outlet, which draws an impressive 4W. The status light + whatever the trickle current it uses to do its function thus dwarfs the standby power of any other electronic device.