The Bell 47B (with floats for landing on water, and saddle fuel tanks) is made by Corgi in 1:48 scale.
Adopting the classic blue and white livery, N.Y.P.D. helicopters upgraded with the Bell 206 JetRanger. My model of this is by New Ray in 1:34 scale.
I have a smaller Bell 204 / Huey UH-1B from Corgi, that was made for their series of fit-the-box models. It’s approx. 1:100 scale.
This Bell 412 (below) looks an impressive 14 inches long with over-hanging rotors. With opening sliding doors, it’s made by New Ray in 1:48 scale.
Finally, I have two versions of the Agusta A-119 Koala - a larger New Ray model at 1:43 scale, and the detailed Amercom edition at 1:72.