What is the best alarm clock sound?

You obviously don't have small children demanding to be read to whilst you're still, essentially, asleep.

We have a clock that has an illustration of a British wild bird at every hour, and plays a recording of that bird's ong on each hour. It's bloody great. It has no alarm function, but I suppose if it did it would be crows or magpies.

magpie's are annoying. they sound like demented football rattles. i have been known to shout at them to shut up on bleary sunday mornings.