I don't see how anyone can top FDA as an agency. I'm actually quite a fan of the EU regulatory framework, but they have too many players in the mix for effective regulation, I think. And, to do them justice, are much newer at the game, like most of the other agencies out there.
A year or two ago, an FDAer I spoke with at a global harmonization forum told me that everyone always fusses at them about not being more "flexible" when it comes to harmonizing, but...whenever they get together with the other agencies, the other agencies don't want FDA to be flexible. They want FDA to show them how they do it, so they can do the same.
That was my impression from talking to regulators from the other agencies as well.