Before kids, I sat by the window, as I love to look out.

I would read a book or listen to music, or sleep.
I love taking pictures out the windows!
Now, the kids want the window seat, so if it's a small plane, I get the aisle, and on a bigger one, I'm stuck with the dreaded middle seat. (each DD gets a window, and DH and I each sit next to one of them). But I can still lean over and look out.

With the kids, I don't read much. They bring books, i-pods, snacky things, etc, but there's a lot of "Mom, can you put my i-pod up and get my book?" "Mom, I want a snack," and the dreaded, "Mom, I have to go." We do keep the carry-on with all the goodies under the seat so I don't have to keep hopping up to get it out of the overhead bin, but it never fails that they have to go to the bathroom at different times. I try to avoid going myself if I can, but on a long flight, there's not really any hope of holding out until we land.