Canon Directional Mic for Canon Camcorders: $139 Shipped (30% Off)

This is the DM 50 directional microphone for Canon camcorders that use the Advanced Access Shoe (such as the Canon Vixia HV series).  I've got the HV30 and the built in microphone is weak.  This definitely picks up sound a lot better.  Four out of five stars from 30 reviewers.