Does anyone know a descent "cartoon" render-er plugin for 3ds max?

VRay, Brazil, Mental Ray

i think Vray, finaltoon most powerful

Vray Renderer Is Best For Cartoon Effect Animation

Illustrate is a plugin that renders cartoon.

Vray toon is better option 

For a powerfull plugin that allows you to render cell shaders, look no firster than Cebas Final Toon. By far the best out there and with a ton of features.

For cartoonic effect you have to use "VRay Toon" effect. Its very useful to create cartonic type renders.

Press8 for apply this Vray toon. Hope it will help.