Long Haul - aisle. I often get up to stretch my legs and go to the lav (comes from drinking so much water) and I hate stepping over people. Short haul - window. I do not need to do those things and hate being interrupted by someone who does. Commuter planes - always window. Being so much lower gives better views.

But Ken Hamer above had it right. The Bis class on AC/CP on the 767 has one seat that is both. When travelling alone (the usual case), there is no seat that can beat that! CP is 1-2-2, AC 2-2-1.