This isn't a A vs B thread, just list your favorite for each.
Favorite Boeing: (and favorite of all time)
757 of course!!!
Photo © Patric Borg
Photo © Jan Szidat
I like the -200 more than the -300, but they are both the most beautiful aircraft ever created.
Not a big fan of Airbus, but if I had to pick one, it would be the A320:
Photo © Bill Hough
Photo © Justin Idle