A panel of former players voted for the All Blacks flanker, 25, above team-mate Dan Carter - last year's winner - Australia's Chris Latham, Springbok Fourie du Preez and Irish lock Paul O'Connell.
New Zealand dominated the IRB awards ceremony in Glasgow, where they reclaimed their title as team of the year.
The favourites for next year's World Cup made it a hat-trick when coach Graham Henry scooped the award as coach of the year after a stunning 12 months in which New Zealand won the Tri-Nations and embarked on an undefeated tour of Europe.
The only success for the home nations went to England flanker Margaret Alphonsi, who won the Women's Personality of the Year award.
France fly-half Lionel Beauxis was voted outstanding under-21 player, while Rugby World Sevens champions Fiji took the honours as best sevens side.