hmm... Sennheiser's not bad, considering how large they are, but they do have some stinkers mixed in with their good stuff.
I would say Grado, but their lineup is basically 3 models with only minor differences between them (from a design standpoint). They are pretty much the definition of "consistent", though - in their sound, styling, etc.
What about Ultimate Ears? Their products range from budget to ultra-high-end, and seem to be pretty much universally liked (or beloved, in the case of their customs), with the exception of the super.fi 5 EB, I guess. I'm gonna give them my vote.