Caravanguard is the one I use although the CAMH has a good reputation. I was with C&CC at one time but changed as I was unhappy with their changes.
Other decent companies include NFU and SAGA if you fit their age requirements. Before you insure with Ripe check out google on their claims service . I have never used them but they come in for some criticism here.
Look for a five star DEFAQTO rating as a start, if one is not quoted assume the worst and ignore Trust Pilot and similar ratings as they are normally praise for the setting up of the policy and cheap deals which are meaningless. Always google their claims service which is what counts.