I don't think Melbourne's exhibit is better then the ones already mentioned. It's land area isn't very big and is all sand. And the exhibit on the left is my favourite of the two but is never in use and now only holds common carp.
Thanks again to everybody who participated in this thread. I´ll try to wrap things up with a couple of comments:
It appears as if there is not a single pygmy hippo exhibit anywhere in the world that is truly breathtaking? But a very good combination would have been:
The indoor enclosure at Aalborg (totally brilliant!), combined with the outdoor enclosure of Givskud or perhaps - not mentioned by anybody in the thread - Whipsnade´s: