Here's one for the "scariest moments outside a helicopter" list - Landed a 105 in the top of a really pretty (aren't they all) waterfall - tail over the drop and skids were under the water; I bounced it a few times and it felt good so I gave the OK for the pax to deplane and waited for the rundown. Joining the happy campers, just as I stepped off the skid she rotated on the aft of the skids, going tail first over the waterfall.
In a flash of self-preservation I leaped back onto the front of the tube and she slowly came back down. It was the last waterfall I ever landed in.