Life Insurance Carriers are rated by independent financial rating agencies (AM Best, Moody's, and Standard & Poor's, to name a few), and those help you compare and determine the financial strength of each insurance company.
The type of life insurance policy that is best, depends on the need it is to cover. For instance, lifetime protection is best provided for by a permanent life insurance policy.
Whereas, if you are on a budget, or have needs of 30 years or less, then a term life insurance policy may be the better option for you.
Here's a list of the best life insurance companies and their financial strength rating from AM Best Company.