Certainly all of your personal possessions. However, you can't take items that are permanently attached to the property. It's true that there are some gray areas. Use common sense.
I looked at a foreclosure yesterday afternoon in the community I live in. The home in good condition would sell for about $650,000. This one was priced at $499,000. The owners had pretty much stripped it. The ceiling fans were gone, leaving the empty junction boxes in the ceiling. Most of the switch plate covers were gone. They'd taken the refrigerator; it'd been replaced with a small, dumpy one. There was something (maybe a trash compactor) that had been at the end of the kitchen island. The device had been removed, along with about 2 square feet of the hardwood floor where it sat.
So, use common sense. Take what's yours. But leave items that are (or are intended to be) permanently attached to, or conveying with, the house.