Caerphilly - Dai Havard. Small abattoir with a very personal service. Dai butchers brilliantly, not like some abattoirs. Will cut exactly what you want. Very happy to take my pigs there. Have watched them being stunned and stuck and have no complaints.
Maesteg, mid Glamorgan - Maddocks Kembery. Family-run business with their own butcher's shop on site. Again, friendly service.
Cinderford, Gloucestershire - Ensor's. Big operation, very professional, and the slaughtermen have always treated my pigs with respect and patience.
BUT, as it's such a big operation, you might get stuck behind a triple-decker lorry with the haulier forcing pigs down ridiculously steep slopes. Happened to me a couple of times and the terrified squealing set off my pigs - previously lying quite calmly. If this happens to you, drive around the block for a bit until the lorry has gone.