My recent domestic flights in the 738 and 739 had rows 23 and 24 as exit rows. I pre booked (and paid) for 23 A and 23 F. The hard arm rests were quite OK. If the view of the ground and Himalayas is important, then row 23 has less obstruction from the engine. I chose the A or F seat based on view opportunities.
10 A/F in my opinion is the best.