Top 3:
Gatwick 65 weekly flights 5 airlines (MT/D8/TUI/EZY/BA)
Stansted 51 weekly flights airlines 7 (PF/EZY/RYR/LS/BA/MT/TUI)
Manchester 69 weekly flights 6 airlines (BA/RYR/EZY/TUI/MT/LS)
Info taken from Google flights so apologies if any info incorrect.
It's great that people have such a wide selection of flights to choose from, but from the airports perspective it must be annoying having the bulk leave at near enough the same time as each other. I thought it would be in the airports better interests to have a more varied timetable?