Recently I had to get my own mobile phone service and decided to forgo the standard post-paid cell service and go prepaid. Decision was largely cost based since I already had my own GSM phone and planned to buy a Nexus 4. I did quite a bit of research and ended up with Straight Talk service
Straight Talk is a MVNO (Mobile virtual network operator) that leases network capacity from T-Mobile USA and AT&T. To sign up you either order a SIM from their web site or you can pick up starter package at Walmart. I did the latter option. In the package they provided me with 2 different mini-SIM cards and a micro-SIM card. SIM cards are really T-Mobile and AT&T unbranded SIM cards. Pick the card that is supported by the phone e.g. if it’s a locked phone like AT&T use the AT&T SIM, change some of the phone settings (APN) and off you go. Quality of the signal is the same as if you used T-Mobile or AT&T. I picked unlimited everything plan for $45/month with a T-Mobile SIM. If you sign up for auto refill they cut it down to $42.50. Drawback is lack of international roaming and iffy customer service ie. hold times can be 30-40 minutes.
Another option I considered was T-Mobile’s prepaid service called Go Smart which is similarly priced
https://www.gosmartmobile.com/
I decided against it since cost was similar but with Straight Talk I have the option to switch to AT&T if I ever find T-Mobile coverage inadequate. That said Go Smart does have a wider array of calling plans so it may still be a good choice.
While we are at it I can also recommend an inexpensive VoIP service called GalaxyVoice. I use their free-tier which gives you up to 60 minutes of outgoing calls a month and all I pay is for taxes and 911 compliance ~ $3/month. You just need to pay the signup cost of $25 and get your own SIP device.
An extra bonus is that their web site is fairly unsophisticated and easy to automate for certain things :-) e.g. forwarding my home phone calls to my cell phone