There are some decent pubs in NZ but most of the drinking establishments in NZ are really bars rather than pubs.
Beer-wise the selection isn't as good as the UK. Lots of lagers but very few bitters and ales (note that Aussie bitters are actually lagers as well).
There are a few ales; summer ale and winter ale are seasonal and are pretty good - but are normally served cold as they are definitely on the lager side of the beer range. I've seen a few IPAs as well. Guinness is available in most bars and pubs.
And agree with the above posts about the rubbishness of US beers - Sam Adams and micro-breweries excepted of course! Reminds me of the canoe joke which is definitely not suitable for a family forum!