I worked for a company in the Bath Road (right opp 27R) when I was a sprog in the 70's At lunchtime, I'd spot from the car park of the 'Heathrow Hotel', almost next to the r/w. Anything from Viscounts to Concorde, and of course the 'grippers' being thrown into reverse in the flare- I was doing my PPL at the time, and being ignorant, thought this most strange!
At Gatwick, you could then spot from above the passenger walkways, directly over the aircraft. The Laker DC10's were too high for these, but still parked close enough for a good pic!
It is sad that now everything is so 'uniform'- As a now 'elderly' spotter, going to St.Maartin next March with TimBucks before they inevitably close the beach due the H&S police!(One thing I promised myself B4 I die!!!)