In keeping with the subway theme, I thought I’d post a photo of the subway system that I’m most familiar with: the Metro in Washington, DC.
By contrast with the NYC and Toronto subways, you could say that the DC Metro is much less varied, with every station conforming to the same waffle-maker-like wall texture and general domed tunnel shape. However, the uniformity in the DC Metro has its appeal: the architecture is beautiful and it feels very spacious and elegant inside. And they did a great job of lighting the walls from below for a more dramatic and artistic shadowed effect. The DC Metro has its own character, and I love it.