From my own experience, I always spend more than 15 thousand Naira monthly on Data,  struggling to find a better data plans for my solution,  until I was introduced to Glo . Although the the don’t always have active network on data , but I enjoy my data now , 
Imagine my data now do expired
That’s why I consider them as the best on data plans , if you do spend a lot on data , try Glo  , they’re the best