rotorspin,
Er, define 'best'.
In the eyes of the customer, 'best' unfortunately often comes down to 'best price'. So regardless of reliability, punctuality, aircraft condition, pilot deportment etc etc etc, the 'best' is often seen as 'best value for money'.
So, any of the London operators would struggle to be the best
VIP corporate helicopter charter firm for Scotland. (And vice versa).
Or, why Haughey Air Ltd would really struggle to be the best for the SE!
(Or anywhere outside of the NW, really).
'Best in the UK'? It wouldn't be possible to determine (IMHO).
'Best for each major region in the UK?' Now, there's a discussion worth having!