I buy from quite a few:
Hasbean - generally lighter roasts, but their single origins tend to be fantastic
Rave - signature blend is a straight forward coffee, not too complex, but fresh and easy to extract.
Extract- great range of coffees, their original espresso is a personal fab
Allpress- redchurch blend is on the darker side of medium, smooth, rich, with lovely intensity, another personal fav.
Right now I'm favouring steampunk coffee. They are a local firm near to where I live, bu the owner hans-erik used to be the lead roaster for artisan roast in Glasgow and Edinburgh. He knows how to make some utterly gorgeous roasts and I've not found anything I enjoy more yet. His velos blend is stunning both as espresso and in milk.
The other few are square mile, union and dear green. But I don't buy from those so often.