Looking to upgrade from a Nikon D3000?

The D3000 was the first SLR I ever got and I love it, but I'm looking for something that will be more manual & better in low light situations. I definitely want to stick with Nikon. Preferably under $1500.

I LOVE my d7000.It's a bit more pricey than 1500, though. I originally only bought the "starter kit", and have added as able.
perusing amazon, the kit is now 1200

If you're comfortable buying a used camera, I'd recommend a used D700. I've never shot with a D3000, but have a D3100 as a backup for our D700. The D700 is a great camera, and significantly better in low light than the D3100, tho' it is only 12 Mp. It is a full frame camera, however, so you'll need FX (full frame) lenses. Also, it doesn't do video, so if that's important to you, maybe a D5200. I doubt it'll be as good in low light as the D700, tho'.

No DSLR will be more 'manual' than the D3000 - it has full manual control over exposure. THe most important factor in image quality (after user skills) is the lens.

If you are only using the kit lens (18-55mm) then you're better off getting some decent glass - fast primes or zooms (f1.8 for primes or f2.8 for zooms). You will really notice the difference in low light situations.

If you really want to upgrade the body, the D7000 would be a good choice.