NewsRob is an RSS/Atom newsreader that auto syncs with Google Reader. Its UI obviously borrows a lot from Google Reader, but NewsRob adds offline caching and many other configurable features, like how many unread items to display at once. Plus, NewsRob seems to sync faster than other Google Reader wrappers.
To make this work best for offline reading, make sure to check the option to download simplified web pages and also change it to readability. Then under view options, change the view to ‘web’. These are the best options to let you read things where you don’t have a data connection (eg NYC subway).