In MF, the best 35mm SLR for me is the Pentax LX. I love the layout of the camera, the gorgeous viewfinder, and the metering system.
In AF, it's a tossup between the Pentax MZ-S and Nikon F100. I am a Pentax fan, so I tend to side with the MZ-S. I love how nearly everything can be done on the camera without ever removing the camera from your eye or shifting your grip. It's also small and well built like the LX. I tend to like small cameras and small lenses, so the MF/AF Pentax cameras (namely the LX and MZ-S) are my choices.
Also owned an MX and loved it. I just preferred the LX's metering system, viewfinder, and great exposure counter better (it counts forward and backwards, making it easy to remove film mid-roll if necessary).