I have a D40 - currently waiting on delivery of my
http://www.bhphotovideo.com/c/product/247091-GREY/Nikon_2137_Normal_AF_Nikkor_50mm.html
Reputedly great for portraiture and low light, super very fast and ridonculously cheap.
Really cant think of a better way to blow a grand at this stage!
Edit: I don't 'feel' good about Tamron ans Sigma lenses, just cant bear the nagging uncertainty in the back of my head that something is amiss - futzing with settings cos I see 'something' wrong and knowing somewhere back there that it could be the budget equipment... is that snobby? (or simply stupid).