I think I have it right.

1. left/right of TV
2. front/back of TV
3. up/down of TV
4. clockwise/counterclockwise like a steering wheel
5. clockwise/counterclockwise like flipping a dinner plate to your left/right
6. is it like flipping a dinner plate at/away from the TV?

P.S. I had a Gravis Destroyer Tilt for PC and it wasn't even fun as a novelty (link). I am not sure if that was because of implementation or what but I did not like it.

Right on all accounts, m'boy!
*sherlock holmes bubble pipe*

Great examples, and I'll add a bit for anyone who's confused...
1,2,3- The normal "3 dimensions" movement. Up/down, left/right, away/toward. No rotation.
4,5,6- Are actually rotating about an axis.
4-Steering wheel.
5-The direction of turning pages in a book. Or flipping a plate left/right.
6-Flipping a plate forward, or better yet, casting a fishing rod straight ahead

And the best motion-sensing games are fishing titles. Turns a boring experience into something quite refreshing. Other than that, I agree with the second part too. Motion sensing isn't that great, really.

you would never finish a race in gt if you used the controller as a steering wheel