New Zealand slang is heavily influenced by Maori language and manner of speaking, and it's generally used by both pakeha (white NZ'er) and Maori without offense. We call each other by those names, by the way.
"Eh?" - pronounced 'A', is used at the end of a sentence when expecting a reply.
"Give it heaps." - 'Try your best!' ('heaps' generally means 'a lot of')
"Aw, true?" - 'Is that a fact?'
"Wot, ****?" - 'I dislike your tone, sir.'
"Wonna go?" - 'Care to engage in fisticuffs?'
"Nah, oi/ow." - 'Nay.'
"Oh, nah, yeah." - 'Verily.'
"'sup, ow?" - 'Hello, sir.'
"Oh nah he's a good **** eh." - 'He is a gentleman and a scholar.'
"He's a mean ****." - 'Truly, an exemplary pillar of society.'
"Giz a drink oi." - 'May I have some of your beverage?'
"Giz a bickie." - 'Please hand me a biscuit.'
"Chuck us a full one!" - 'I would like all of the beverage.'
"Let's get a mean feed." - 'Let us feast!'
"That's a mean car, oi." - 'What an exceptional automobile.' ('mean' generally means 'very good')
"Yeah mate, fuckin' stoaked(sic)." - 'Yes, I am quite excited."
"Oh, cracker!" - 'Wonderful!'
"She'll be right." - 'This situation will improve.'
"It's munted." - 'This is damaged beyond repair.' or 'This is a disgraceful situation.'
"He's nicked it!" - 'He has stolen my property!'
"I'll shout you tea, cuz." - 'I will buy you dinner, my friend.'
"Ta." - 'My sincere thanks.'
Anyone who's played Far Cry 3 might be familiar with these; the local islander characters were voiced by New Zealand Maori.
But the best example of exaggerated Kiwi slang is done by John Clarke as 'Fred Dagg'. YouTube that; it's funny shit oi.