·Time Warner Cable
·Verizon Online DSL
The libraries I've sued seem to be okay
The Fredericksburg, TX library relatively recently launched a WiFi network. The place is running of a 10/1 TWC business class cable connection. Not the fastest out there, but decent, considering TWC's pricing goes from high to insane when you ask for more bandwidth than that. The library internet, at least for the WiFi, is not run off of the city's fiber network, but you wouldn't want it to be that way either; there's only 20 Mbps to go around, and that includes all the schools.
In St. Lucie County, FL the libraries are on the county network. All AT&T. Bandwidth there is around 20 Mbps last I checked.
So while some libraries aren't getting enough bandwidth, there are plenty that are.