Which Nikon DSLRs have an autofocus motor in camera body?
I have a Nikon D3000 and a lens which has no autofocus motor. But under the lens, I have found a screw which rotates with the focusing control. My D3000 does not have any autofocus motor inside the camera body, so, I am thinking of changing my camera.
How can I find a list of Nikon cameras which do have a built-in motor?
I'm voting to reopen this question. It is not so broad that the existing answer doesn't answer it succinctly and correctly. If newer models that don't fit into the listing convention used (which is used flexibly enough that all cameras released since the answer was written fit into the way the answer is written) in the answer are introduced in the future, it would be a simple matter to add them to the appropriate list in the answer.
Nikons with autofocus motor in body: D50, D70, D80, D90, D100, D200, D300, D7xxx, D6xx, D7xx, D8xx, all pro models (D1, D2, D2, D3, D4, Df). Models derived from those (e.g. D300/D300s, D3/D3x, etc.) also have AF motors.
Nikons without AF motors: D40, D60, D3xxx, D5xxx.
I think a D90 would make an excellent upgrade to you D3000. All the bodies with AF motors have better sensors than the D3000 except some of the older ones: D50, D70, D80, D200.
Full list can be located here (cameras without AF motor are highlighted yellow).