If you are looking for a pay-as-you-go plan that is easy to maintain, I would have to recommend taking a look at Virgin Mobile. Both my husband and I have cell phones that we rarely use except when we travel, but we like to always have them on hand in case of an emergency. We used to have Tracfones, but were always charged 2 units per minute (instead of 1 unit/minute) because we used them out of our local calling area.
With Virgin Mobile, we have to top off our phones every 90 days with $20 in order for our account to remain active, and the minutes rollover. We set this up so that it happens automatically - it's been a no hassle, affordable plan that works well for us.
When we had a family emergency and were using our cell phones constantly over a period of 2 weeks, we were able to add more minutes directly from our phones, which was a huge lifesaver. Also, when my husband had his phone stolen at the gym, I was able to immediately suspend his account online, order a new phone (they were having a promo, so the new phone cost us $10), have it shipped to us for free, and then reactivate the account online. Good stuff!
You have the option to order lots of different phones. My husband and I are more budget-minded than feature minded when it comes to cell phones, and appreciate the ability to get a phone for about $20 without any promos.
We get good service in our area, and have not experienced any hassles to date. I have to give Virgin Mobile two thumbs up!