The words 'Favourite' & 'Handling Agent' in the same sentence are something of a contradiction in terms.
Luxair in Luxembourg have to be the worst, they have the monopoly and don't they know it!!!
CircusAir in Bristol, in the old days, used to be good, one of the few decent CircusAir's around, not sure how they are now.
Derry Airport Handling were also great for being called out in the middle of the night to open up the airport when BFS was fogged out. The firemen & airport manager come ATC were great for unloading 'budgie' freighters.