This is a subject I can talk about for ages, I've worked on helicopters for more than 30 years now and I agree with DerAdlerIstGelandet , you can't go past the Black Hawk, I am trained on 13 differant Helicopters (B204-UH1-B, B205-UH1-D/H, B212-UH1-N, B412, B214ST, B206-OH58, B206L, B407, Sikorsky S-70 Black Hawk, S-76, S-92, Eurocopter AS332 and CH47 Chinook and worked on 6 other types, B214B,S-61,AS330, AS365, Lynx(naval), AW139, I have also had contact with Mil8/17 and Mil 24 operators.
my opinions
Best battlefield assault/utility- UH-60 Black Hawk, great machine just about indestructable, the latest models UH-60M 2050HP FADEC engines, glass cockpit with 4 MFD's(multi function displays), the family refined to a fine helo without comparison (what Australia should have got to replace existing Black Hawks instead of bloody usless MRH90- 14 of 46 delivered and still not accepted into service yet! though rumor has it Australia may yet get 17 UH-60M's for spec ops role as the MRH-90 can't do it!!!), the MH-60M of the 160th (night stalkers) has the 2750 hp engines of the S-92 in it, radar, flir, inflight refuel the ability to be configured as DAP's (Direct Action Penetrator) gunships with 30mm cannons and rocket pods. my dream machine! (I assembled the first Black Hawk delivered to Australia in 1988 and was an engineer/crewman on them for the next 6 years )
Best heavy lift -CH47 Chinook , the F model with similar avionics to the UH-60M and with high horspower FADEC engines , just gets better with each model, though the CH53-K will be one to watch. Though everyone should have half a dozen Mil-26's for super heavy lift , cheap (less than the price of a new UH-60M), can lift 20,000kg but not that reliable and just too big for a war zone unless lost of gunships about for protection.
Best Gunship/Tank killer- AH-64 Apache , the pre emenent gunship in the west (what Australia should have got instead of Tiger, Tiger only used by Germany,France,Spain and Australia, 18 of 22 delivered and only has limited operational status!!, Apache used by US, UK, Netherlands, Isreal, Egypt, UAE, Saudi, Singapore, Japan, Greece, Taiwan and on order maybe by South Korea and Thailand.
Best light recon/spec ops -OH6 little bird pilots love them , can be a bugger to work on but more ruggered than the OH58/206 series
Best naval helo Small-Lynx new models great machines older models with Gem engines absolutly gutless in hot and high conditions,CTS-800 engine much better, one of the most user unfriendly helicopters i've worked on great at its role but I hate it. Good machine in Europe don't try and operate in the tropics or desert
Best naval helo Medium/Large- SH-60 Sea Hawk family, like the Black Hawk family matured into a bullet proof machine tried and reliable (thank god Australia saw sence and got the MH-60R to replace out existing Sea Hawks and not the NH-90, the government learnt there lesson with the army's MRH-90 and are now stuck with them)
UH-1 family , The mighty Huey weather a UH-1H with one engine or the UH-1N /212 or 412 with twin pac a great reliable work horse , bit long in the tooth but held in fond memories with any one who has been around them ( I was trained on them in 1982 and still work on 212 and 412's)
Mil 24 Hind- one of the biggest con jobs the Russians pulled on the west fast and heavily armed but not that manouverable and cannot hover with full fuel and weapons load must do running takoffs , cannot do hide and popups like western helos
Mil 8/17- what a truck reliable cheap and good hot and high performance , build by Russians so can be easily maintained by semi skilled countries (ie third world), throw away helo , designed for war use 6 months lose it or throw away , ok for third world countries that dont fly much not good for western countries were machines are kept 20 plus years.
CH53 - good machine the K model will be a beaut, similar cockpit to S-92 with 5 MFD's and 3 huge high HP FADEC engines the Marines deserve good equip.
AH-1 Cobra family , the start of the Gunship era getting old in the tooth though the Zulu model is still lethal, don't get in fromt of a Marine in a Whiskey or Zulu Cobra!
AS332 Super Puma- Good jack of all trades helo not as good as Black Hawk in assault or spec ops role , but better general people carrier, you can do just about any role in a Super Puma but it is not the best in any role, I have operated them on UN support work and they performed very well.