For me- the 9 am flight is the easy winner. For TPAC flights I find that I board, watch a movie, eat etc and then am ready to sleep. That puts my sleep mid-flight. Then, landing mid-afternoon means I clear the airport before sunset and get several hours to walk and recover then eat and head to bed. Within one day I am on the local schedule. For mw, leaving in the middle of the night and arriving at the crack of dawn both make the transition harder.