Ones I can think of off the top of my head:
Powerups
Doors
Floor Hatch
Marine/Hero
Ghost/Hero
Firebat/Hero
engineering Bay
Barracks
Command Center(not sure)
Beacons
You can enable/disable protoss buildings. Enabling/disabling them will make them powered/unpowered.
If you wanna cloak a unit, theres a tutorial in the database.
Be careful what u disable, sum will make sc crash, anyway, off my head, dont disable obersers whyll u can see them.