I use Ultegra SPD pedals with Shimano mountain bike shoes. I like them because I can walk in them without looking too weird. On a couple of my bikes, I have "campus" pedals, which are SPD on one side and platform on the other (these are on the bikes I use for errands around the neighborhood wearing street shoes).

Today it was warm and I rode the Waterford through Golden Gate Park to the Beach Chalet for lunch wearing Shimano SH-SD60B SPD sandals.

I'm a late bloomer when it comes to clipless; I really started regularly using clipless about a year ago.