Blender, the open source software for 3D modeling, animation, rendering, post-production, interactive creation and playback (see the features and screenshots). Available for Windows, Linux, Irix, Sun Solaris, FreeBSD or Mac OS X under the GNU Public License.
Straight from thier mouth.
It is a free program that has many options and runs on every main OS.
I posted it here mainly because of the variaty of platforms and it looks to be a decent app. I havent used it yet, but from what i have seen it looks very powerfull and not too complicated.
And who wouldent want This