Not that I don't disagree with you, I think the Coens make better films, but Reservoir Dogs and Pulp Fiction easily qualify as classic. The latter has a rightfully earned spot on AFI's top 100 films of all-time.
Sure, I was referring more to the complete body of work. There are several directors that have one or two classics to their name whereas the Coens are a disappointment if any of their work does not end up being a classic.
It's kinda like the Kubrick-syndrome, the Coens have made so many classics that you are disappointed when they fail to do so with new films. That's different than saying I expect it, as I certainly do not.
For the longest time they were kinda shunned by the mainstream because of their odd quality and flavor that are evident in their movies. Not that the mainstream is any ultimate and final decision maker of what is good and bad, but what it does do is lead to bigger budgets which has been evident in more recent movies the Coens have produced. With that said and much credit to them, they have stuck to their great story telling, character building, and odd flavor even with the bigger budgets.