Help picking out a video camera?

I'm in the market for a video camera. Probably a DSLR.
Price is an issue, so keep suggestions cheap lol.

We need something that can shoot 1080p, and performs well in low-light. An audio input would be great, but not necessary.
Right now I'm looking at the Nikon D3100. I've shot with it before and love it.

I don't mind getting an older camera if it works.

The only interchangeable lens camera that has video as it's primary function is the Panasonic GH series, the GH2 is almost as good as the GH3 (same sensor).

Doesn't overheat and get noisier or even turns itself off like a DSLR (particularly Canon), has a sensor which is just the right size (within 2mm of being exactly the same size as 35mm film is when used in a cine camera) so no interpolation, most of all it has much more bit depth, bit depth determines how much data is recorded in each frame the higher it is the better the video quality, but the faster it will fill cards and makes for (much) bigger video files. The GH2 can be hacked to over 80Mb/s which gives you cinema quality video, viewable, with all the enhanced detail, on a large 40ft cinema screen, no DSLR will give you anything close that kind of quality.

Nothing comes close to the GH2 for high quality video at a low price especially with a really good prime lens e.g. Leica, Angenieux etc. Other DSLR cameras will beat it for stills, but for video it reigns supreme. The GH3 is more of the same with some slight improvements.