#1 annoyance - rip-off credit card charges. £5 extra on top of a £80 ticket - 6.25% surcharge - nothing but an unscrupulous additional income stream for the airline.
#2 annoyance - baggage charges - as family of four we paid over £70 in luggage charges to go from IOM to Spain via LPL - thanks Flybe and Easyjet
#3 annoyance - tinny, crappy music blaring out when the aircraft is on the ground - "Flybe unplugged" being the worst offender by a mile.
#4 annoyance - seating allocation - why huddle everyone together at the back of the plane and leave the front 8 rows empty (flybe on a recent flight to LGW) at least the FA usually has the courtesy to suggest that people move seats once the doors are shut.
#5 annoyance - no I dont want to buy a f...ing scratch card.