I think a lot of the choice depends on your use of the weather. We use weather underground, because I have a personal weather station which is posted there. Since weather.com bought them, they have progressively destroyed that website and made it harder to access as well. Unless I’m mistaken though, it is the only site available for those of us that have personal weather stations.
I also have a personal weather station and I wondered the same thing.....if there is another site to link my station to. I constantly have issues with WU being down but biggest issue is linking my web cam to it. Frustrating
Here is my local weather website - http://daculaweather.com/