I already have a Galaxy S5, that is fully paid off. I would like to keep it. I want a voice only plan for it. There is WiFi everywhere I go, so a data plan is just throwing money away.
The answer to that will depend on whether your phone is a GSM (AT&T and T-Mobile) or CDMA (Sprint and Verizon). Also, is your phone unlocked?.
I have a GSM Galaxy S4 and I use AT&Ts GoPhone, a pay as you go voice & text service. You might also use Tracfone, but that will again depend on if you have the right phone in your location (go to their website to find out).
What kind of usage do you expect? How many minutes/texts per month? Your choices with the traditional providers will be more limited as they may force you to have data if you have a smartphone. However, there are many prepaid providers out there that provide all different combinations of services. Many of them require you to top up the account with X, and then charge you independently for the services you use (.10/min, $.10/txt, $Y/gig). You can have access to them all, but you only get charged for what you use.