If you're strictly looking at who is a "top" life insurance carrier, American General, Prudential, and (to name a few) may fit the bill. If you're looking at just financial strength ratings, such as who has an "A++" financial strength rating from AM best Company, versus A+, A, A-, then MassMutual and may be insurers to consider, as they have the highest financial rating that is given by A. M. Best Company.
There are hundreds of life insurance companies to choose from out there across the USA.
A life insurance policy from one insurance company may be right for you, but not for someone else who has different risk factors, such as, age, gender, or health issues.
You may want to consult with an independent insurance broker to determine which insurance carrier will be good for you and your life insurance policy.
Here is a life insurance buyer's checklist to help you review what to consider when going through the life insurance buying process.