For a while now, I’ve been picking my flights based on aircraft type and my historic success of aircraft dispatch reliability. This generally means I fly Southwest on the B737 and avoid the A319/320/321. I haven’t had a need for long-haul flights, so I don’t have experience with any of the other types, with the exception of the B757/767. They are aged aircraft, but I don’t have any particular problem flying on them.
-Gary