USAA was founded in 1922 by a group of U.S. Army officers to self-insure each other when they were unable to secure auto insurance due to the perception that they were a high-risk group. As initially, the company only offered insurance to military officers and it is still not open to the general public (you still need a military affiliation), this technically is a military related question.
That said, for someone in the military or who access to being insured by them, they can't be beat. Sure, just as with other companies, their premiums will be a little higher (the only con) for those under 25, but they are easier to get insured if you have a few blemishes on your driving record.
Others may have lower rates, but usually a lower rate means either higher deductibles or very bad claim service. If your deductible is really high, what was the point of you having the insurance in the first place? If you can afford a $1000 deductible, you can afford $1000 cash payment for damages.
Additionally, some companies do not insure in all states or overseas. USAA does. Some companies will drop you if you PCS to another state. USAA won't.
I used to sell insurance and very few companies come close to what you can get from USAA AND you can modify your policy yourself online at anytime. They don't even need to visually see your vehicle to get initial insurance. Some companies require it.
Back to rates and service, while USAA may not have the lowest rates out there (but almost), their service is better than ALL of them. For example, I was once insured by GEICO, with an extra rider on some custom stereo equipment in my vehicle that was not factory. I only had the stereo for 2 weeks before my vehicle was broken into and the stereo and speakers were stolen. Friggin' GEICO depreciated it by 50% for replacement! Are you kidding me? That's what I paid extra for? To be ripped off? I dropped them and went to USAA then and there.
A few years later had a windshield shatter just as I was leaving for work. Called USAA and they had Safelight out to replace it in under an hour. No deductible...just a handshake and thank you. I was only an hour late for work. Some other companies would have had me waiting all day AFTER they sent out an assessor.
Who cares how low your premiums are if the service sucks?
So with all that said, what do you think?