I always preferred aisle or window, that way, there's only one person next to you. You can always try requesting either aisle or window when you check in, and sometimes they give it to you.
Drink a lot. The dry, low-pressure air is hell on your system and it's easy to get dehydrated, making everything that's already uncomfortable worse. You can avoid multiple trips to the airplance bathroom by staying away from tea, coffee, and caffeinated sodas (all of which make you want to "go" more often
) Alcohol may help for other reasons, but it doesn't count as "drinking" in terms of preventing dehydration and in fact makes it worse.
The "beverage cart" may pass by only once or twice, but don't be afraid to flag down the attendant and ask for more to drink at any time (except during takeoff, landing, or turbulence, etc)
Good headphones are a must. However, even the greatest pair of headphones will have great difficulty covering up the noise.
The most stressful time of a flight (for me, at least) is immediately after takeoff until you stop climbing. After that I'm pretty cool.
Hard candy or something to suck or chew on for a long time is a must as well. It'll help pass the time and also help keep your ears open.