leica M, bar none. Marty Forscher, formerly of professional camera repair in nyc, called it, the nikon f and the canon f "hocky puck" cameras and for good reason. I prefer the M for quiet, ease of use and holding and pure sex appeal.

the leicaflex sl2 is another favorite -- like the F1 of Nikon and Canon fame, you can dent things with it but not the camera...quietest slr shutter going, supreme quality, a joy to use.