I shoot primarily in manual, but will switch to Av some times if light is changing, I also have a couple of custom modes on My canon S5 when I want additional saturation or contrast. I really prefer setting exposure by what I see in the viewfinder or screen, makes me analyze the whole picture and keeps me aware of what the cameras electronics are telling me.
I use M mode all the time because I like playing around with exposures and Depth of Field especially when comes sunset or taking pictures of windows to overexpose the light. Second option would be A for moving objects.
Depending on how fast the action is I usually use M mode especially for landscapes. When the action or light is changing all the time I will switch to Av mode and will rarely go over f4 because of sharpness.
It depends on waht I am shooting most times I use the S mode My camera also has two SP modes. In the case of sunsets and twilight shots I use The preset sunset setting in the SP mode to enhance the color In the case of Shooting Christmes lights I also use the preset night setting for a clearer shot.