I’m not particularly fond of cheese with crystals, so don’t buy it too often. But the Red Fox, mentioned upthread is good. It’s readily available in British supermarkets.
Although a Red Leicester, it’s not made in the county but in Whitchurch , Shropshire. Belton Farm makes a wide range of regional cheeses - Cheshire, Double Gloucester, Sage Derby, etc.
If you’re in to Red Leicester, although no crystals, look out for Sparkenhoe which is the best of the genre I know. If you come across the Vintage version, even better. That’s aged for 18 months, as opposed to the 6 for the ordinary cheese, so much drier.