I've had a bit of a change of heart on this lately.
Long haul I'm still going to sit as far forward as possible with a view to not being help up too badly at immigration. Window/aisle is a bit debatable - I love looking out of the window but I also like being able to get up and wander when I want.

For inter-European shorthaul in Y however, I am now a back of the plane person. It doesn't make much difference in terms of immigration but it does minimise the hassle over luggage space and maximise the chance of getting the row to myself. However I have switched from window seats to aisles with a view to making a reasonably swift exit from the plane.