who's the best ever Opposition Leader?

I noticed this quirky article by Barrie Cassidy today which lamented the lack of great Opposition Leaders in recent memory see it here .
Well apart from the nature of the job which makes is hard enough to produce "great" leaders, it got me thinking that there's really only been one of note. That surely would have to be Kevin Rudd?
He came to the job in late 2006 with the next election less than a year away, and while he had a public profile as a quirky policy wonk nerd who appeared on morning television to discuss the politics of the day, this alone was surely not enough of a CV to wrestle the levers from a political animal like PM Howard?
So over the following six months he built his reputation up as a serious policy driven politician who was going to do something about climate change (an issue that Howard eventually faced up to kicking and screaming all the way), reduce cost of living pressures, get out of Iraq, yet keep the American alliance strong.....and of course rip up Workchoices.
So looking back over that time, he never really put a foot wrong, he often led the political agenda, addressed the Chinese Premier while on a State visit in Mandarin while Howard churlishly looked on, and much to Howard's frustration, offered bipartisan support every time he tried to wedge Labor.
So I would disagree with Cassidy, we HAVE had at least one great Opposition Leader in our time.