the cell providers deliver all the same ****ty services,
non is really reliable and each has its downs in specific areas.
i would take a good monthly "Plan" from one and connect a cell for prepaid cards as a backup phone with an other provider, so you are more flexibel in case you depend on the phone for business/work.
just for a private housephone i wold take one of the numerous available Vonage services connected to the Internet.
i don't know what companies are available in other areas,
here in PC i use a Vonage with a 305 Miami area code at the office for my communications with my 95% american and Canadian customers, at home i use one of our PC local Internet provider "Bec-Tel", less than $100.- one time fee for the equipment and installation, $10.- monthly fee with i think 150-200 fre local minutes included, additional minutes are with Tax around 4-4 1/2 pesos per minute.
that's cheap and in my case their srvices are up and running with very few downtimes per year mostly due to electrical outs from the Elec. provider, which are anyways very rare in the PC area.
the Vonage with the 305 Miami area code costs me $30.95.- per month and provides unlimited minutes within the US and Canada(includes Great Britain, Spain France and 2-3 more european countries which i don't remember at the moment), they offer different world plans where a mixture of different countries around the globe are included. that phonage never had an downtime unless the office internet connection isn't going down.
hope that helps
Mike