Some really big items: In the attic, the birdcage really knocks em flat out running in 2 hits, the purple room's bed is a good one, as is the polar bear, or moose head. The bathtub can be really effective when you get to lvl 3 abilites. So can any kind of glass. The mirrors/ glass covered cabinets can be rapid fired. The paintings that looks like trees but drop bombs is one of the fastest. the bushes at the bottom of the stairs can be useful too. The car is a real whollop, but hardly anybody goes in there. Too bad most of the smaller items are useless, as is most everything in the music room.
Number one item has to be the set of plates, the level three scare is pretty much an insta kill.