For me, it varies by flight. If I am flying DL from SLC-LAX, I always sit in a D seat, so I can see Las Vegas and maybe I can see the fountain show at the Bellagio, or the Volcano Eruption at the Mirage. If I am flying over an area of the country I want to see that day or night, I ask for a window. If I am flying a DL 757 and I know we will exit out the center door, I sit in 6C, because I'll be the first one out the door and into my car out of the airport.

Otherwise, any non-bulkhead aisle seat (b or e, not c or d) will do. I'm not picky, am I?