It all depends where and how you ride. I found a touring bike to be a good compromise for me. It has most of the efficiency of a road bike for the road (many gears, light, fast and efficient), yet it can also take a beating and supports almost any 700 tires from the skinny 23' to 38' so I works fine in muddy paths and in the snowy winter as well.

Then again I don't do really off-road riding