As a fellow claustrophobe....

Bulkhead seats!! If you have one of these - no one will recline into your space which is my particular issue, or an exit row because even if they do - their seat back is that much further away from you.

Unfortunately these are the popular seats on most flights.......

If I am in a "normal" seat, my personal choice is the window so I can look out on open space, and there tends to be a bit of "leanaway" room there too. and as soon as the person in front reclines their seat - I recline mine to maintain the distance. You sometimes do have an argument with the person behind objecting to you reclining though - I have had a major argument with one bloke pushing my seat back up objecting because he was over 6ft tall.... I pointed out that it was my seat and I was perfectly at liberty to recline it if I wanted to - and if I didn't he would get a full blown panic attack in very short order. The cabin crew sorted him out for me!