Today I've been going through some exercises for an Accent Reduction client I'm seeing tomorrow. We've been over the story of 'Arthur the Rat' roughly a million times and, while there's still a few things to work on, she's understandably going a bit mad.
So I looked out my old friend 'Comma Gets A Cure'. If you've ever used the IDEA website (and I recommend it if you're looking for an accent in a hurry as it tells you the age of each contributor and when the recording was made, as well as the area they're from and where they've subsequently live) you'll be familiar with Comma. It's a long and silly story about a goose, but it uses a huge breadth of sounds so it's a great exercise.
Let's hope my client enjoys it!