There are two worlds of ringtones. There are the "this is my favourite song" ringtones and there are the "holy shit why didn't I think of that" ringtones. Music, pretty much by default, falls in the first category. The second category, that's harder to define.
And that's where you come in. What's the best, wittiest ringtone you've ever heard or used. I'm thinking sound effects, clever but not annoying pop culture references, you know, something that's not just dumb. You got any?