Good defaults also let you give power users complex features while keeping the common case manageable.

For http://ratchet.io , we're currently working on overhauling our notification system. The new system is rule-based, extremely flexible, and can be as complex to configure as you want it to be. But we're providing sane defaults -- e.g. "email everyone on the project when a new error occurs in production", "if Pivotal Tracker is set up, create a story for each new error" -- so it will (hopefully!) work just fine for most people out of the box.