In pocket, vibrate. I live where all the people of the world live, so I won't be able to hear any ringtone anyway (ROFL).
In office/home, Mute, because the phone is always in front of me.
In places where I can't afford to have a call missed, I turn up ringtone volume all the way, and guess what I have as my ringtone, LOL, it's the one from Crank (the movie). Even a deaf will hear that bloody thing. If anyone knows a ringtone like this (funny, yet related to normal phone rings) then do inform me.