If you're an experienced 3D modeler and don't want to pay the earth for your software, then open source application Blender is definitely worth a look.
The Blender project is based in the Netherlands and encompasses modeling, animation, rendering, post-production, interactive creation and playback. With it, you can create high quality 3D graphics, movies and replay real-time interactive 3D content. Such is it's renown that it's become a popular tool with professional animation studios across Europe involved in the production of high quality 3D content.
Before you even attempt to use it therefore, you're going to need a grounding in 3D modeling or at least know where to start with one. The documentation accompanying Blender is highly extensive however and if you've used other 3D modeling packages, it won't take you long to pick up the basics. There's also a dedicated support office on hand and thriving community forum in case of problems. Unfortunately, the latest version still does not support sound on Intel Macs although this will surely be resolved shortly.
It's amazing that Blender is entirely free considering it's depth and power. If you're a 3D animator working on a budget then you should definitely give it a go.
- Many changes which can be found here: http://www.blender.org/development/release-logs/blender-257/