Cheapest and best are contradictory..it all depnds on where you live and what promotions they're running at the time..
For example...Verizon and Comcast have different packages and prices all over the US, but within their own seperate companies..
If you can find an inexpensive quality high speed net provider, then Vonage is the cheapest/best phone provider in US
but again, what type service you want like type internet speeds and phone options , along with specific geographical location, will determine whats best for you..
I will tell ya, Verizon has the worse customer service of them all...and Comcast communications customer service is usually much better..
Also cable companies don't have all these hidden fees and taxes which usually add another 40% to the price that Verizon quotes you...
I myself have used them all, and still do, and use different companies depending on which house location..
Generally I will say that cable is the best and cheapest usually, but again thats just generally, if only wanting 1 company...they all have a "double play" ( 2 package bundle) ...internet and phone... that with promos can cost as cheap as $$36- 48 a month for both (unlimited long distance call ID, voice mail etc and fast 5mb internet) for 12 months and no other fees or contracts...U need to shop around your area...just remember Verizon has poor customer service, if ya ever have any problems, anywhere in the US..
Also remeber...whenevr you call any company, the sales dept rep there all differ, and can always give ya a better deal then what they tell ya..so always call back and talk to another one but always keep the name and extension of each that you speak too...they all can be very flexible and offer better prices and deals than a rep sitting 10 feet from them..