The number of sales does not denote the quality of the aircraft. While both aircraft have their merits... its a matter of choice. Some will argure that the later air buses were designed for those who love to push buttons and not fly... while the 737 NG was designed for those pilots who want to have the option of flying the jet or pushing buttons with the same features as the bus.
All airplanes are great... its just that some are greater than others.
Come on... lets face it... the bottom line is about the pay check.