I'll add it to the burgeoning list, tho' truthfully, I'm more fond of Romans than Roman Britain ;)

I'll put a plug in for early English history as particularly interesting. The period from the first Germanic settlements to Hastings is much overlooked. This is particularly egregious when one bears in mind that in the 8th and 9th centuries CE England was one of the most advanced and culturally vibrant societies in Western Europe.