For odorous aircraft, close to the 'top spot' would be dried shark meat in a Valetta (or any aircraft) - not left to 'improve', just carried! Needed a couple of weeks with the emergency windows open to approach normal.
Certainly in the 'Top Ten', a whole Camembert, bought in Pnomh Penh and left in the Devon nose compartment, in the Bangkok heat for a weekend, would 'rank' quite 'high' !