Which would you choose?
If you want video capability, choose the D90. If you want to use Nikon AI and AIS manual focus lenses with metering, aperture priority AE and focus confirmation in the viewfinder, and want a rugged, well sealed body, choose the D300. I use manual focus lenses and have no interest in shooting video with an SLR, so the D300 would be an easy choice for me (I use a D700). Other people will have very different priorities.
Another vote for the D300. -- Paul Giverin British Jet Engine Website:- www.britjet.co.uk My photos:- www.pbase.com/vendee