Opinions vary, but my personal favorite on the 744 is 4F :
-no seat in front of you.
-no seat behind you.
-plenty of space behind the seat to stow your carry-ons within arm's reach.
-magazine rack right in front of you. It has a small ledge on which you can place trays, glasses etc., thus allowing you to clear your tray table when you feel like it, instead of waiting for the FA
to come along.
-you can place carry-ons against the magazine rack without impinging on legroom.
4E has the same advantages, but being right-handed I prefer having the aisle on my right and the videoscreen on my left.
Second choice would be 77A or 77K, upper deck emergency exit row. These seats have handy lockers in the windowsill, which aisle seats 77B and 77J obviously lack.
If the C cabin is not full, I'll take any other seat, provided the adjacent remains unoccupied.
The C cabin in the brand new 777 has received poor reviews.