Blender is probably the best free modelling program out there. I personally use Maya, as I just love the hotbox and all of its features (and there's just so much learning material) -- but it's expensive, though you could use the PLE version for free.

I think you'll find that a lot of the gaming development community prefer to use 3DS Max, and a lot of the other industries (such as film) use Maya. They are pretty much the same thing, except that Maya has NURBS, and they are amazing (though confusing to work with at first).

Houdini is probably the most amazing piece of software, with their latest version just being released. I believe it is the only 3D application that is solely based on working with nodes (Maya does, but that's more to do with materials and rendering).

If you want some extremely awesome learning material and an all-round good community, go to 3DBuzz (google it, though they are on a tour for the month).

(By the way it doesn't matter which one you learn, as long as you are comfortable with the user interface and way that things are done and of course if you like any extra features. Because either way, you will be working with polygons and they are the same in every program)