Armed Citizen's Legal Defense Network.
They will post bail in states without bail bondsmen which many of the other won't. (Very important in Illinois.)
Their coverage is the same in all states which some of the others don't do.
They cover all weapons and physical actions for self defense which some of the others specifically exclude.
Some of their coverage is more generous in some areas than others offer.
People who have had to use them were happy with how they were treated.
Picking coverage is very complex and confusing. People also have different needs and geography may play a part in it.
Here is a real world example: A Galva, Illinois farmer defended himself against a drugged up 20 year old body builder with a gun on the edge of his property. The Henry County Sheriff's Office responded and did not charge him. It was discovered that the shooting took place just over the county border in Knox County. The Assistant State's Attorney in Knox County directed the Knox County Sheriff's Office to arrest him at the hospital at which he was being treated and charge him with murder. What a difference a few yards make.
He sat in jail until bail could be raised by his family. His attorney fees were over 100K. He did not have any coverage.
Springfield Armory is in Henry County.