There are also demo versions of 3DStudio Max and other programs available. If you are looking just to make models, why not try some of the Free programs linked above? WINGS is excellent and updated almost every week if not every other day. As TonyJ said, you may like the workflow and interface of one program more than another. Remember, it's not the program that makes great art, it's the person using it. The fastest way to do your best work is to find a program you are comfortable with.