This was my first real "professional" 35mm camera and now I have two of them. They are heavy cameras, but a joy to use. I don't think there is much more you could ask for from a mechanical 35mm camera.
Pentax 645
Picked up this camera with 3 lenses for a good deal. It is easy to use, and the shutter/motor sound is great. The buttons used for changing the shutter speed are a bit clunky, but overall it is pleasant to use and takes great photos. I prefer it to the Mamiya 645 which I have also used.
Polaroid SX-70
This camera is awesome. It's just really amazing how small it fold down, yet it can still take great photos? I installed the "frog tongue" according to a video tutorial to prevent jamming & allow the camera to still close fully. People love it when you can take a photo of them, and just give it to them then and there.
