Theme Hospital/Furniture

Bench
Used to keep patients happy while queuing up for a room. Place lots outside popular rooms such as GP's Office and some in other parts of the hospital.

Plant
Plants help keep waiting patients happy (also keep them from vomiting) in the corridor, but require watering by a handyman. Also keeps staff more content when placed in a room. Place the plants close to the door so that handymen will have to walk less.

Radiator
Keeps the hospital warm, which helps keep patients and staff happy. You can fine-tune the corridor coverage in the hospital management screen where you can also look for hot or cold spots. This is irrelevant for rooms; each radiator provides a set amount of heating (up to 78%) depending on the room size.

Drinks Machines
Place around your hospital so people don't get thirsty, and get some money in the meantime.

Of trivial note, the vending machine has a product-placed KitKat logo despite selling drinks instead of confectionery.

Fire Extinguisher
Supposed to reduce the chances of your machine breaking down or blowing up.

Reception Desk
One of these is required for each receptionist.

Bin
Helps keep your hospital free from litter. Since these can only be placed within rooms, place them next to chairs the patients sit in, behind the screens or next to the door so that the patients will use it.