I would suggest a high strength coat & cloak nylon or silk thread as they are far stronger then most types of thread. In my experience these threads also snag on things less often, yet that won't stop the button from snagging. The lighter weight nylon thread is not always worth it though. As others have also mentioned, sew the button tight on the jacket. If the button sewn tighter to the jacket it is less likely to snag something. I often sew more stitches then needed and use 2 or 4 pieces of thread when replacing a button and have not had any issues with buttons after I have sewn them back on.