Animation is fun...
Animation is fun...
If you want 2D, the most frequently used app is Macromedia Flash, and it's not that expensive either. You can do some really cool stuff for web design with flash as well. There's Flash standard and Flash Pro, I think Flash Pro allows for better integration with Video and Web.
Anyhow, most applications for 3-D modeling and animation can be pretty pricey.
The ones I hear about most frequently are also pretty complex. There's 3DsMax, Lightwave, Maya, and Softimage. Those are some of the heavy hitters. They're used for feature films and Sci-fi series. There are some less expensive applications, like Carrara Studio 3, and Ulead's Cool 3-D. There's also some sweetening plug-ins you can integrate into your app, like Deep Paint 3D 2.0, and Wonder Touch. Also, Adobe's After Effects can be used with some of these I believe, but I'm not sure as to how extensively it's used.
Here's a really helpful link to a forum for motion graphics. If you look around on there, you'll probably find something or someone to assist you on your quest for discovering the best 3-D app. Have fun...
http://www.mograph.net/board/