I like Cheese with fruit in so my favourite is probably Wensleydale with Cranberries and a soft cheese with garlic and herbs. Cheddar is great for cheese on toast though :)
I like most unadulterated cheeses. If I wish to add stuff to it I can do that for myself, although I do try the added extra stuff on occasion, diet allowing. I do avoid veined cheese though. It may be psychological but the texture reminds me of having a heavy cold. And knowing I am deliberately eating something that has gone mouldy, well it's just wrong. One doesn't eat green furry bread, why would one eat cheese in the same condition.
Our overall favorite here in the U.S. is Jarlsberg… but absolute favorite cheddar is an import from Ireland (who'da thunk?). The brand favored is Kerrygold, especially their Dubliner Premium Aged Cheddar...