You need to decide based on the level of coverage offered for your particular animal. Not who is cheapest or who has the cutest kitten photo.
If you're wanting to cut down on your costs in general, pet insurance is an area where there is scope to make reductions. One way is to ensure your pet is kept healthy, which should reduce the likelihood of ill-health, resulting in fewer visits to the vet and the possibility of reducing the cover you need.
Pet insurance provides cover for all sorts of things, including offering a reward if the animal is lost or stolen. It may also pay kennel fees if you go into hospital, cover the cost of cancelled holidays if the animal becomes ill and pay compensation if it damages property or causes an accident. However, in many people's minds, the purpose of pet insurance is to deal with vet's fees and so that's the main area of consideration when choosing a policy.