Forgot to mention the newer Nikon FM series(FM, FM2) that also seem to go on ebay very cheaply. FM3 has an aperture priority Auto-exposure mode so it does not count for an all manual camera. I have had an FM2 which was a wonderfull, very light camera. The aforementioned NIkon F, Nikkormat FTn and Leicaflex SL are solid, heavier cameras that really feel like you've got a precision machine in your hands.
