For anybody interested, I did a study last year on R44 accidents. At this stage it is restricted to the UK only, but I will extend it to at least the US next time I have a spare few days.
Certainly points to a very low accident rate ralative to other types (esp. in relation to hours flown, there are quite a lot of R44's about in the UK now).
The results are also the basis for my belief that effective supervision and on-going briefing/ debriefing can significantly minimise the accident rate (I can't see the correlation with the annual LPC at the moment, introduced in FY2000).
My gut tells me the worst accident rate in the UK by type is the Gazelle.