Purely personal opinion, but Solid Edge was the easiest software package for me to learn. It also happens to have the workflow that matches the way I think. (Tell the program your end item goal -- a protrusion; and it tells you the steps you need to take to get their -- plane, sketch, protruded distance. This workflow, as opposed to creating a plane, creating a sketch on that plane, then using that sketch to create a feature only to have the feature tell you that your sketch doesn't meet its requirements after the fact.)
--Scott
For some pleasure reading, try FAQ731-376