How do I choose the right smart phone?
First think about the size.
A small one like the Moto G is comfortable in your pocket, where a larger one makes it easier to read a book.
The price also goes up with size such as with the largest Moto.
Storage is also a key consideration. If you'll be working away from wifi or have a lot of photos you want available anywhere, you will need plenty of storage.
Any of these phones should be bought as an unlocked phone as opposed to a no contract phone.
Then you can pick your carrier at whatever price it features you prefer.
Consumer Reports and Best Buy can help you choose.