Analog is the oldest and most basic choice. You often get a plain vanilla phone for free, but you probably will be required to sign a contract for service, normally for a year. Costs for limited phone use are generally less for analog than digital service. The more you use a phone, the more cost effective digital service will be. In other words, don't be talked into digital phone service unless it fits your use.
Cellular service is highly competitive and rates and services keep changing dramatically.
If you decide that service with a contract is the best for you, sign up for the shortest possible contract period. Beginning January 16, all wireless carriers must transmit 911 calls regardless of whether the caller is a subscriber or not. If you want emergency calling only, get a used phone and make sure it can be charged. You can get an adapter and run the phone off your car battery when you're traveling. An analog phone will probably work just fine.