I personally would stay away from Autodesk stuff unless your are wanting to invest a SERIOUS, SERIOUS amount of time, money and resources into getting people up to speed on their 3d software. Maya and Max both have near vertical learning curves and prices literally 10x that of sketchup.
Modo302 may be a closer alternative, but I have no experience with that app.
I'm looking forward to see what else comes up in this thread.