For cheap and easy, I really like Poser. It's very quick to learn, but still has enough meat and potatoes to it to do decent looking stuff. It's got basic IK, a walk designer and a nice-looking albeit slow renderer. There are several different lip-synch tools available for it, and a lot of add-on content. Dennis has written some plug-ins so you can even use AC3D to make morph targets for your Poser characters.
In a far distant second, I like Milkshape. Milkshape is also very easy to learn, but it is very barebones and it has a *lot* of bugs. There's no IK or anything of the like, so it is much more difficult to get acceptable results out of Milkshape unless you are already excellent at hand-drawn animation, and even then it is time consuming. It also has a lot of limitations as far as skinning, so blend weights don't always work as they should either. However, it is cheap, and it supports a lot of file formats including many popular game file formats which is great if you're into making mods.
Another Poser pics showing the kind of quality your can get out of the renderer if you know what you are doing. It's a re-skin of Jessi I've been working on:
The eyes still need work, but I'm happy with the direction it's headed.