I use AC3D in combination with Poser. AC3D will export OBJ files which can be rigged and animated in Poser quite nicely. Poser, like AC3D, is very inexpensive and very easy to use, yet you can still do professional-looking work with it. Whereas AC3D is strictly a modeller, Poser is strictly animation software, so they make a very good combination.
Here's a pic of Poser with a character I built in AC3D, so you can see what it looks like:
