depends on if you want things handy w/o getting up
I prefer rows 3-4, either side, due to the availability of the underseat storage. In F, especially on a 757 there's plenty of room for my backpack or briefcase and my legs even though I'm reasonably tall. Really anything rows 2-5 are pretty good. Even though row 1 has all kind of room at head level, the lack of the storage spot doesn't work for me.
YMMV.