Well I hate to post negativity on Xmas day... but! In my opinion the worst has to be...
Cumbernauld.
When I dropped in there on my solo XC qualifying flight parking was a little tight on the tiny apron. Never mind, I got a space, and went to get my form signed.
The owner was unhelpful, nosy, condescending, and down right rude to me. (He was also wearing 3 stripes, even though he is merely a PPL - legal?)
I was informed that if I hit the company terrorhawk - newly parked next to my PA-28 in a difficult spot - I would be sued.
NO offer to move it, NO offer to help me move my aircraft prior to engine start, NO offer to be marshalled out of my space, NO help from the crappy "radio service" who didn't even have the courtesy to reply to my RT.
As you can probably imagine, I was a somewhat nervous, inexperienced low hour type pilot, well on the way to the PPL skill test. This didn't help my situation one bit!
The route that day was Prestwick - Perth - Cumbernauld - Prestwick. And boy was I glad that I had stopped at Perth before reaching CBN.
I have nothing but praise for the proficiency and helpfulness of the staff at PERTH. Especially Colin who operates the radio service. Nothing was too much bother.
When I reached CBN the pressure was on, it's just outside the busy GLA zone, it's almost impossible to see from the air as you approach, due to its hidden location on an industrial estate, and for some strange reason that day it was busy!
There were many aircraft in the circuit as I joined overhead. (I'd kept at 2000' rather than coming in for a right base join to enable me to spot the airfield sooner).
I slotted in behind a slower aircraft than mine, and gained too much on him resulting in me going around (my fault not his, it was close but he missed the 1st exit and couldn't clear the runway in time), I was a bit nervous, very glad to get on the ground, could have done with a coffee and a 10 minute break, but after that, couldn't wait to get out of there and talk to the professionals at GLA and PIK!
Cumbernauld, I've been to you once, and in my opinion that’s FAR too many times. I would advise any of my friends and flying colleagues not to go there unless in a 7700 situation!