Insurance companies from my family's experiences:
AAA: Expensive, but they pay out quick and often more than you'd expect (well worth the cost if you have a good driving record IMO)
Allstate: Get a laywer, they always wait until you take them to court
Mercury: Get a reciept of your payment EARLY. If you're a day late and get in an accident you're not covered even if they have already cashed the check (they will refund that one check though)
21st Century: I hope you don't need a car for 3 months, I was without one when mine got totaled in a pretty clear cut case of them being at fault.