Before you decide what kind of car you would like, what kind of area do you have to run it in. Do you have an area you can use a Trail truck/rock crawler? Do you have a large flat smooth location you can run a speed car on safely? Terrain makes a big difference so it's something to keep in mind.
For a crawler are you looking for something you can goof around on trails and climb average rocks, or do you want something that is more comp oriented that can climb almost vertical cliffs?
For a fast car do you want something just to play around in parking lots or do you plan on dropping a bundle on a speed runner, because most speed runners are dedicated to that and don't do anything else.
It helps us to help you if you give us a little bit more info.