I shoot in 100% manual mode, because I get a lot better photos that way. Believe me, I'd rather just point and click and be done with it, but that just doesn't happen with me. There's always something changing, like a cloud passing by, which in turn kicks up some wind.  Or I'm shooting a humming bird, and a hawk suddenly lands on a branch three feet away. The aperature  and shutter speed priority modes don't work since I tend to change both depending on the circumstance. Sometimes I might sacrifice shutter speed for aperature, or vice versa.

Keep in mind that I'm pure amateur and I shoot nature stuff. I would think different styles would call for different approaches. If you're shooting indoor portraits for example, one of the portrait modes, or even one of the priority modes would work just fine.