I’ve been using TurboCAD Deluxe for a few years now, version 20 is my new favourite. It is a good choice for the serious hobbyist – doing a number of things extremely well. The first is that it has a robust set of tools for 2D work. This is important because many materials are essentially flat (such as plywood or sheet metal) or you may need to produce views and layouts in a 2D format. But, it is also very versatile for creating 3D objects by combining 3D primitives (cubes, cones, etc.) or by extruding or revolving 2D shapes. Another reason to consider TurboCAD Deluxe 20 is for its ability to import and export many different file types including .dwg (AutoCAD), .skp (Sketch Up) and .stl (used for 3D printing).
(I’m going to refer to the above as the “short” review, I hope to publish a more complete one soon.)