It's hard to put into words the frustration of a junky cell phone signal. On one hand, the fact we are able to communicate to any degree with devices that fit in our pockets is cool, but getting reliable data is also a big deal these days. Maybe Glove can help. It claims to have the ability to tell you which network is best for your usage after just three days of analysis.
Glove uses GPS to track your location during the learning period, then factors in when you were using your phone. Those two bits of information can tell Glove where cell service is most important for you personally. Crowd-sourced data is used to offer a recommendation on which carrier you should use.
The UI looks great, but it will take a few days to decide if the recommendations are equally good. The service is currently only available in San Francisco, New York City, and Israel.
Update 2/22/14: Here's what the result looks like in San Francisco. Needless to say, Artem was less than impressed by the winner, Sprint, as he escaped it for another carrier due to endless frustration with the quality of mobile data after 13 years of loyalty about a year prior: