Aisle. I'm tall, and all my height is in my legs. Also, I don't have an iron bladder so I'm one of those people who do need to get up once or twice each flight.
The rest of the flight,I'm sound asleep and don't notice if people climb over me.
Luckily, most of my long haul international flights are on business so I'm in Business class and it doesn't really matter since I try to get the centre section where both seats are on the aisle and then I sleep until we land.
It is a true blessing

to sleep every flight I get on. I just can't seem to stay awake even if I try
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I wish I were 1,000 miles away