What Tablet is Right for me?

For starters, I really don't *need* one, I actually need a navigation GPS. However, the idea of a touchscreen tablet in my car is pretty cool to me. I have an iPod Touch, which I love, and wanna keep for my music. But if I can find a good tablet (not forking over $400-$900 for an iPad or Xoom), that I can use for video/movie playback & navigation, that would be great. I saw the Google Android 2.2 & ViewPoint and others...any suggestions people?