I'm just taking this list as what it is: A list of very well crafted websites that hopefully inspire others for their own work.

And really, what's wrong with style over substance? It's not like a firm needs to have a Reddit/Gmail style of a design.

I, like you, use Facebook, Gmail, and Reddit quite a bit. However, I don't consider their design to be as outstanding as their functionality (which I know we'll disagree with). Thus, I wouldn't say they are my favorite web designs.