I'd like to view most articles of Wikipedia while I'm offline. I understand that it doesn't have to be or probably could be all articles, but a good subset would be nice.
AllofWikiOffline app is the best I have seen and has reasonable update pricing if your offline copy needs updating in the future.
I'm the author of an app called "Wiki Offline" for iPhone, iPad, iPod Touch, and Mac. It provides the whole text of Wikipedia for offline consumption (images and tables can be imported for individual articles if you have an internet connection).
It is a very mature, highly rated product, with experience enhancements like tabbed browsing, a read-later queue, bookmarks/folders, customizable fonts, etc.
The other two "competing apps" are AllofWiki Offline and Encyclopedia. I encourage you to check out all of them.
I downloaded and access the whole wikipedia offline by following a tutorial given here(using kiwix) - http://www.superpctricks.com/2013/10/download-entire-wikipedia-and-access-it.html