Actually I understand how Ansett767 feels.
When I fly (so far only domestic flights) I try to get as close to the front as possible. I have ridden in the front
(very first row) and ridden in the very last row and I notice a difference.
Other than the obvious difference in seats next to an emergency door, I think that visually seeing a whole plane of filled rows in front of you for 20 hours can give an illusion of cramped space whereas if you can only see 3 or 4 rowns ahead of you it might make you feel less congested.
As far as turbulence, personally I do believe that you encounter it more in the back (just my uneducated, unclinical theory ((so please not sharp replies))
I think there is sometimes a whip factor like when you ride on the back of a bus.
(I never get sick at the front, but I get nausous at the back on busses)
It has been my experience that sitting on the wing can be quite unnerving as well. Sometimes the wall next to you moves in and out as the wing bends up and down whereas it seems when you sit at the front all the action slides past you. When you sit at the back you can see the pitch of the aisle when the plane is climbing and desending and to some that can be unerving cause the back rises last and the front can appear a good story higher. But when you sit in the fron you dont notice the pitch (unless you turn around and look at the back of the plane) and who wants to look at 300 heads bob up and down during turbelence?
Again, you dont see this at the front, bit see a very stable, calming wall usually.
Again, no scientific proof here, but I find it reasonable to see how someone would feel and see more movement sitting in the back.
As for me? I like the front.
As for your legs?
I would stand up at the airport and not sit down before boarding your flight. I also go to open space next to the emergency door and stretch