Personally I use both the D80 & D200, it all into what you shoot.
Note: Lens make the shoot, not the camera, but I find how easy it is to get those shots can make a bit of a difference. The D80 I find easy to use in situations where your on-the-fly or on-the-move and it gives you manual control, the D200 will give you slightly nicer shots on the same glass but takes more time with the settings to get a good shot so if your not the focus (like in a photo shoot) you'll need quick hands or longer post processing time.
Here is a big difference I have noticed - You can shoot with non-cpu lens on both cameras (check the capability), and each will tell you when you are in focus, however on the D80 many older lens you can use only True Manual, which can make it a pain as you need to guess (take a picture and check) on your lighting; fortunately there is a histogram that is easy to use, but FYI.
By recommendation - These are both great cameras, I would recommed going with the D80 if your not doing a lot of model shoots and use that money for better lens. If you already have good lens, go for the D200 with the magnesium body.
D80 - Landscape, Events, Simple Portraits
Both - Macro, Action, Outdoors Good Weather
D200 - Models (Professional Shoot), Rougher Weather (Because of the Case)
P&S - Underwater (I'm talking snorkelling, professional scuba shoots go with either but you need to invest heavily in lights, waterproof cases, etc.)
Good Luck!