Take a look at this site - It can give you a good review of what is out there and what to think about.
They are supported by the mobile internet community - so they are unbiased
Like others will state - you need to define your requirements / budget first.
We still work while on the road - so we have data plans on the big 3 cell providers. I do not count on any campground WIFI if you have to work or stream. Have not had one cell provided that is best in every locations.