1. "I'm feeling a bit warm, would it be possible for you to move to the window seat?"
2. "I have to re-arrange my bag, can you move to the window so I can put it on the middle seat for a little while".
3. "I hear the view is really good on this flight" (make up some land formations they might want to check out).
4. "Wouldn't it be more comfortable at the window, that way we both have more room to spread out"
5. "I'm a bit claustrophobic, can you please move into the window seat"
6. "You seem to not be wearing deodorant today. Can you please move to the window seat as you smell".