New Zealand’s rugby team does the Haka before international matches. (Here’s the Haka of the All Blacks Wikipedia entry.)
When Munster hosted the All Blacks at Thomond Park in November 2008, the four New Zealand players in the Munster team performed their own haka prior to the All Blacks.
Watch the video of the Munster Haka. Listen to how loud the stadium is. Remember that Munster is hosting, then pay attention to the silence as the All Blacks step forward and do theirs. And after all that, just search for “All Blacks Haka” and watch a bunch of them—the best are when the other teams challenge them and stand their ground a few feet away from the chanting All Blacks while the crowd goes nuts.