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I've heard good things about Chief Architect, ACAD lite, Vectorworks, and some others. These are all in price range above a thousand dollars.
Chief has a junior version called 3D HomeArchitect that can be found for under about forty bucks that saisfies a lot of folks.
Here is a link to another discussion that also contains other valuable links and information http://forums.taunton.com/tp-breaktime/messages?msg=23758.1