My brother is a frequent traveller, over 6' tall and has lower back problems. For him, leg room is paramount. He tries to get the exit row seat and if that's not possible he uses his points to upgrade to business class.
My husband is even taller. His flights are usually booked at short notice so that there is no way he can get the exit row seat. He then prefers an aisle seat in the middle (no money or points for business class available).
Since I travel with kids 90% of the time I'm not allowed to sit at the emergency exit. I always go for a middle row, aisle seat. As someone mentioned, there is a small chance that you get an empty seat next to you as well.
I hate window seats as my experience has been that they can get really cold. My kids love them though to put their head against it for a rest.
The only seats I've seen that don't recline much and that I really try to avoid are those in the very last row.