Could you elaborate how exactly? What would you rank lower than Uber?
Now there is an easy, cheap, fast, and reliable way to get anywhere in the city, any time I want, without planning ahead. That bar my friends are meeting at that was two busses away and not worth the hassle on a Tuesday? I'll be there in fifteen minutes for the price of my first beer. For those who drive: no more worrying about parking or how many drinks you had.
Ranking companies which had less impact on my life than Uber seems like a strange exercise.
Beyond that, Uber's usefulness really depends on locality. There are some places in the world that actually have functioning, acceptable taxi systems, like Seoul, where the prices are reasonable and the drivers are generally fair.