It all depends upon what you like. The window seat allow you a bit more comfort when it comes to sleeping; you can lean against the window. A window seat allows you have to access to more natural light so you can look out the window, read, or just daydream. You won't be asked to move in a window seat so you can remain totally undisturbed. You are trapped in a window seat so you must ask the middle seat and the aisle to move whenever you want to get up. If you are the kind of person who needs to go to the bathroom often or needs to walk around, you are not going to like being at the window.

The aisle seat allows you to stretch out at least one leg. You can come and go at will. You can exit the plan more quickly from the aisle than you can from the window. You may have problems sleeping in an aisle if anyone next to you constantly has to get out of his seat for whatever reason. You may get bumped into by the carts. People might bump into you as they walk by. You are at the mercy of the window seat person if you want daylight; if he puts the shade down, there is really very little you can do unless you wish to be confrontational.

That said, I always prefer the aisle. I have to be able to get up from my seat and I enjoy the little bit of extra leg stretch.