I got my helicopter rating about 15 years ago in an R-22.  I think
most schools these days use Robinson's because they are reliable, and
relatively inexpensive to operate.  They have some idiosyncrasies -
low rotor mass, but are a blast to fly.  If you have money to burn,
you could learn in an R-44, but the 22 is a great ship to learn on.
Bell 47s are still around, but as said require a fair amount of
maintenance.  Also Hughes (Schweitzer) 300's.  Be happy to discuss
further.

Dan Ballin
LEG2 N386DM