When we were in the process of moving into our new apartment in Madison, our car broke down. We used another cab company first, but when we called them the next morning, it was going to be a five-eight minute wait to even talk to the dispatch.
We called Green Cab, talked to the dispatcher immediately, and didn't have to wait all that long for a ride. We used the service several additional times until our car was fixed, and it was efficient and the drivers were all friendly (if a bit eccentric) and knew where they were going. The only downside was the price, but since I'm not used to cabs in general, my opinion on that isn't as useful.