For the past 7 years I've had an AT&T Go Phone and it works great in TV. They are now called AT&T Prepaid Phone. I know they have smart phones, but I use a Flip phone.
Usually if I need to look anything up, pay a bill, purchase something, I have a desktop and a laptop computer at home. So when I'm out and about I only need a phone for emergencies or to call home, so I find a flip phone is perfect. I get 1000 minutes a year for $100, that's about a cheap as you can get. They also started rolling over a few years ago, so now I have about 2500 minutes accumulated, not a big talker on the phone.
Initially the phones were only $10 at Walmart or Walgreens, which meant when the battery died after about 3 years, it was cheaper to buy a new phone than a battery. This last time it quit charging the $10 phones were way higher, I think demand caused the price to go up. I shopped around and found a LG flip phone at the Summerfield Walmart for $26. They don't have them on display, just ask, they are behind the counter.
AT&T Prepaid - Affordable, Flexible, No Contract Phones & Plans