As with all of these things - it is horses for courses.
In London where at HEMS the average flight sector including t/o & landing is 6 minutes, where there is fuel at various locations around the city, and there are number of receiving hospitals, range & comfort and speed are not such big issues. But operating from a rooftop and flying into fairly tight confined areas much of the time does require a reasonable amount of engine power. So in that situation the 902 works very well. However in Canada, the U.S or Oz where the area to be covered could be huge, with little choice over fueling sites and/or hospitals the 902 would be useless. In that situation an
S76 or 365N or 412 would obviously be a better choice. Change the variables again and the BK117/EC145 could be the best option.
i.e there is no best helicopter - just the one most suitable for your operation.