I mostly have default for email/sms/bbmsgr. most of the time I'm waiting for the led flash so I can pounce that I don't need a notifier.
For my ringtones:
General: B.Y.O.B by System of a down (everybody's going to the party to have a real good time)
Best Friend: 1985 by bowling for soup
2nd Best Friend: life's been good by ?
Husband: Let it Be by The Beatles
random other: Pink Panther theme song
Email: Train horn
SMS: Notifier_Sonar
Alarm: THX sound effect
Ringtone: any of the following
- BSG Cylon theme
- The Price is Right theme
- Pacman sound effect
- Battle of the Planets theme