I don't like to lock into a cell phone contract. I have a Verizon prepay account that covers unlimited calls and text, data up to 15 GB but I don't use the phone for web surfing or streaming so 15 GB is more than I'll likely use per month. Data usage doesn't apply if you are connecting to the net using WiFi, only counts when using cell towers. I also think it rolls over unused data every month too.
The phone I have is a 2001 or 2003 Motorola G Play. I don't need anything fancy. I think I paid like $120 for it new. The plan costs me $35/month plus taxes and stuff so maybe around $38/month total. This includes a $5 discount for auto pay and $5 discount for valued customer (I've used Verizon for my cell service for many years). I can even use the phone as a hot spot if I want to connect a computer or other devices to the phone and if the phone is connected to the towers but that eats into the data usage part.
I'm not locked into any contract and I can quit anytime I want with one small detail. When you connect a new phone or different phone to the account, it's locked to Verizon service but after 3 months you can call them get it unlocked it and you can switch it over to any other service of your choice but you'll need a new SIM card for that different company's service. I've stuck Verizon over the years due to the inexpensive plan and I get good coverage just about anywhere I go.
The big three in the nation are Verizon, AT&T and T-Mobile. These 3 players cover nearly 100% of the US cell phone networks and maintain the towers. The smaller services like Mint, Consumer Cellular and stuff use same towers - they buy access to the towers from the big three. For example Mint Mobile uses T-Mobile network, Consumer Cellular uses both T-Mobile and AT&T, Straight Talk and TracPhone use Verizon.