The camera and lens combination I have found myself using most often over the past few years has been an old rangefinder camera (like the Leica M3) and a 50mm lens. I'm not completely sure why this has been the case, the this combination just "fits". I've been focused primarily on candid portraiture. The camera is relatively small and quiet, which makes it nice to use in these situations. The 50mm lenses I've used are also fairly fast, making shots possible in lower light than would be possible with slower lenses. Overall, I'm really enjoying this simple combination.