Finding a good example of a Brummie accent as proven more tricky as I'm either stumbling across paradises where they over accentuate the "twang", or TV personalities where the access is suppressed a little. Ozzy Osbourne is from that area and in his interviews you can sometimes hear the accent showing through. The pronunciation itself isn't hard to understand; I highlighted it because it's a unique accent. I think these days it's mellowed quite a bit though.
This video isn't work safe, but it's the best example of a Welsh accent I could find. https://www.youtube.com/watch?v=HwUrMEZWj5o (this is also probably the accent I hate the most - I couldn't explain why, but it just grinds)
This is the Cornish (south west) accent: https://www.youtube.com/watch?v=8jbxdZE3g80 It's probably the closest to the old Shakespearian English that someone linked to in these comments.