Another excellent proggie that I rarely see mentioned is
Rhinoceros 3D. It's a bit on the pricey side, but if you're a professional or even a serious hobbyist it's worth every penny. Super user-friendly and easy to learn, if still tough to master. Oh yeah, and NURBS rule!
You can certainly model in 3DSM, but it's not the most intuitive and easy to pick up tool in the world for doing that. It does sport the best commercial rendering engine I've yet seen though, and I still use it to import my Rhino models when I'm ready to texture/render.
But if you've got the time and patience to become proficient with 3DSM, then hey, you sure as heck won't regret it!