To me, it looks like these are the best seats:
Business-class: 5A, 5D, 7A, 7D. If the galley behind business-class is only used for beverages then I'd add 8A and 8D to the list, although passengers at the back of the cabin, depending on the purser and catering, may not get their preferred choice of meals.
Premium-economy: 1A, 1B, 1H, 1J.
Economy-class: 30A, 30C, 30G, 30J, 40B, 40C, 40G, 40H, 41A, 41J. If as with other aircraft, the last row (55) is blocked off for last-minute purchases from passengers with elite status then there's always a chance you could snag an entire row on a less-than-full flight.
https://www.delta.com/content/www/en...rbus-a350.html