polaroid cameras...
If you want to use the impossible film, you will want an SX-70 or 600 camera. They should be coming out with Spectra film sometime in the future, though.
As far as price goes, the 600 cameras are MUCH cheaper than the SX-70 cameras. But the SX-70 cameras are down right sexy; glass lenses, manual focus on some, real leather covers and a serious heft to them. SX-70 cameras are also limited by their flash- the older models are designed to take the no longer available flash bars. You can do some conversion, but it is not straightforward.
Many of the 600 cameras come with built in flash- and with the current polaroid films being ~100 and ~400 speed- you need a flash if you ever want to take a photo indoors.
Check out the Land List for details on specific cameras:
Dead Link Removed
And have fun,
Matt