On the A380, my favorite seat is 2K. If that's not available, go with 2A. If neither of those are available, I prefer 1K, as I hate rows 3 and 4 bc they are too close to the galley.
On the 777 I prefer seat 1A, or 1K. If you prefer not to be so close to the galley, then take 2A or 2K. There's only 2 rows of F on the 777 so if you want a window seat those are your only choices.
Enjoy your flights!
-ek202