The Tesco "Creamfields" mature cheddar (their value brand) is actually surprisingly good.
Will confess to buying the big kilo blocks as I use it for cooking and toasties and the like, but they do it in smaller packs too. Used to get the mid-range cheddar for cooking, but it's really shot up in price, taking it into big brand / cheeseboard territory.
I kind of discovered the value cheddar during first lockdown when it was either that or nothing, and I was very pleasantly surprised. It's only fault is that they don't do an extra mature version, because I prefer my cheddar to have a bit more "oomph". But as an everyday all-rounder it works well enough.
For something decidedly more poncy, the Co-op do a really lovely cave-aged vintage cheddar![]()
I like my cheddar to taste like I'm chewing razor blades. Combine that with a 1/4 inch thick slice of Spanish onion and crusty bread and I'm in heaven.