Hi Andy,
Firsty welcome to Pet Forums, I'm fairly new to the forums and already addicted!!
I would recommend checking out the Defaqto rating of the policies available to you, Defaqto is an independent review system that reviews all forms of financial products and awards them stars based on their product Vs the competition in that sector/product. This link to our site may help you as we have already done the leg work in putting together the comparison between some of the most popular insurance policies -
Compare Dog Insurance | ComparePetCare.co.uk
I hope that helps, and whilst I can't personally recommend one insurer, I don't think it's something you can choose based on following the crowd on a forum, but from reviewing the policies available and seeing which plan best suits your pets needs.
Good luck, Viki