My best mate is a partner in an insurance broker, and he advised me to go to Adrian Flux (which is what I did). I figured he'd know better than most.
I did subsequently find a cheaper company called HIC - 0800 121 7424. They explained to me that they're a sister company to Adrian Flux. They were about £20 cheaper, most likely because there was something missing from their policy that made it that bit cheaper.
Insurance companies vary each year and I always end up switching...done Adrian Flux and footman, this year justkampers were the cheapest - although I think they are just a front for someone else like AF - never makes much sense.