The most versatile, easy to use and least expensive E-ZPass I know of is available through the Pennsylvania Turnpike. You don't have to be a PA resident to purchase and you can get it online.
There is no need for multiple passes for trailering, hauling and normal driving like there is with some other states' passes -- one E-ZPass does it all. I have never had an erroneous charge with my pass, using it in all states on the eastern side of the country. There may be others that are just as good -- all I can speak for is the PA Turnpike E-ZPass.
Bruce