Far be it from me to start a childish argument regarding which is better, but having flown both the 737 and the Airbus, the latter wins hands down every time - wider aisles, more space in galleys, simple arming mechanism and generally more user-friendly.
Having said that, it also depends on the age of the aircraft...LHR have some very old Airbus a/c which are very possibly just as smelly and 'knackered' (if not more so) than any 737 down at LGW...fortunately there is a plan to dispose of them sooner rather than later, but there will be a few lurking around for a while yet; they are mainly confined to domestic runs.