I'll bite. Window on everything. I'm an avid window-seat flyer and train rider and can usually spend hours looking out the window and never get bored.

If I have my choice, on longer-distance plane/train travel, I prefer a row where when the seat is reclined (if possible), the headrest is aligned with a wall or other support structure to facilitate easily leaning against it to snooze, with a window immediately ahead of the wall/support beam.

I usually wander around trains and boats and things, particularly enjoying views from the diner/restaurant car and/or cafe car or from various decks and seating types on boats.