You seldomly need more than 15 seconds until you pick up your phone or it's getting annoying. So I had the coolest DS intro ever as a ringtone some years ago. But as dmg said, you write more than you actually really phone these days. So I turned it down and also use a standard ring tone now, one that is as polite and discreet as possible to other people's ears.
Oh, it was the intro of Expresso Love. Of course.
LE