Firstly, congrats on the new Camera
To be honest, to make optimum use of the D300 you need this lens as your everyday lens :-
Pixalo Photographic Equipment Reviews - AF-S 17-55mm DX f/2.8 G - . But for out & out optical quality you ain't going to beat the nifty fifty for the dosh :-
Pixalo Photographic Equipment Reviews - AF 50mm f/1.8 D -