Depends on what you plan on Producing!
If you are going to make video games, I would suggest 3D Studio Max.
If you are going to make short films or want to go into the film industry, Maya is the standard.
Cinema4D is not that great for anything other than 3D text rendering. It is hardly used in the professional world.
If you are looking for something decent and that can run in After Effects, might want to check out Element 3D from Videocopilot.net
It's pretty awesome technology.
However, It *IS* rather limited in what it can "produce"; but it's a great start and will most likely end up being a powerhouse somewhere down the road.
I have personally used ALL of these programs and I prefer Maya over all of the others.
I prefer Maya because it is the industry standard for 3D Cinematography and is used by most of the Larger Film Studios on Big Budget Films.
Knowing it will put you ahead of the game if you ever decide you want to get into the film industry.
Hope this helps!!