Which camera should i upgrade to?

I have a nikon d3000 that i got as a gift, but i think it's time to upgrade. I know it's mostly about the lens, but i think my pictures would come out even better w The only problem i have, is i don't want something too difficult to use, but i definitely want to upgrade. I also want to stick to nikon. Any suggestions?

Added (1). I have 3 lenses.sigma 18-50, tamron 70-200 and nikor 35mm

Why do you want to upgrade?

get another lens, that will have a much greater effect on your photography than getting a new camera body.

what do you like to shoot? Choose a lens based on your answer.

Until you learn to use the camera you have, buying a new one will not improve the quality of your images.

Get a second AF-S lens and enjoy the added points of view it will give you.

The D7000 would be the next logical step up for a Nikon.

Bypass the D5100 as it is not that much of a jump up from the D3000, as the D5100 is still an entry level camera.