H/269-C.
I think the training helicopters are being overlooked.
Most military/goverments use the 300 as the base for their training.
Even though the UH1H or the bell KIOWA are very popular , didnt most of those pilots start out in the TH-269 at some point ?
And even though the R-22 is gaining momentum the Schweizer 300 ( H/269-C ) is still up there.
Other wise i'd have to vote for the Airwolf Helicopter , that never went down and it could cruise at Mach 1 !
HF