Another vote for Elstree from me.
In defence of ATC there, it's only one person who is uncooperative to the point of being dangerous. All the others I've ever heard seem quite helpful and professional.
I wonder how much of the Elstree problems are brought about by the way they've handled things in the past. With so many different circuit patterns, some of them resembling cross countries, they must now overfly absolutely everyone living in the ATZ. They must be p*ss*ng off twice the number they would if they stuck to normal shape & size ones.