I don't want to start a list here but I think it would be nice to have a thread containing your experiences with a particular pipe organ in the UK.
It would be nice to know the amount of manuals, maker, where the instrument is located, your experience with it and possibly even an image!
My list:
J.Walker LTD Organ (Built. circa 1920)
A three manual J.Walker Organ built in the early 1900s. The school chapel used to house a Willis until the 1900s. Then replaced by a Lewis and again replaced with a Walker. It is a great organ to play and I have my lessons/practice there.
Lewis & Co Organ (Circa. 1920?, Restored in the 1990s)
The nearby parish church has a Lewis & Co organ which I go during the weekends to practice on. The Walker is a better instrument because I prefer the structure/feel of the pedal-board. But the Lewis is a great instrument as well.
There is a 4 Manual Harrison & Harrison in the Speech Room but it is hard to access it.