Aldi do "Specially Selected Cumberland Sausages" made from British Pork and contain something like 88% or 90% pork. They're only £2 for a pack and they taste delicious. They also do nice bread and a selection of other nice foods, so we find ourselves heading there to buy a lot of bulk. They're opening a Lidl very close and we find that Lidl usually fares better whenever comparing the two, so that is good.
I'm surprised by the Asda comments, our local Asda is alright, it is big and quite new though. It's also ok for bulk shops, as is our Tesco.
I do try and get most of our meat from local butchers though - it's so much better than supermarket stuff.
So in conclusion, we shop everywhere!!