The Ah-64D Apache is simply the best combat helo/gunship ever built. But at $25 Million a piece, they are expensive as hell.
As for the rest of them excluding the HAL LCH, they are all near about equal. Cannot comment on something that does not exist.
The Ka-52 is a good bird with high power, speed and maneuverability but its
effectiveness is reduced by lack of good weapons systems.
BTW, does anyone have any news regarding the weight issues with the LCH?
The Mi-28 although sharing same configuration of the ah-64, its much more effective. Its more powerful, climbs better, accelerates much faster (especially with its new 2400shp engines) and is much more agile. Mi-28 mechanically is far supirior to the ah-64. The Ah-64 is less agile then a westland lynx (i know this because from Farnborough airshow 2008), its not the most agile helicopter of its day, its not that much more nimble than a mi-24.
Mi-28 is also far better armoured and more survivable than ah-64D. It has duplication of the main mechanical components and hydraulics as well as advanced armour around vital areas such as cockpit, engine nacelle and rotor blades.
Mi-28 has far better fire-power, the 2a42 30mm weopon is a BIG and HEAVY fast firing cannon borrowed from the bmp-2 IFV, its far more accurate , faster muzzle velocity (hence more accurate and better penetration) than the Chain gun on the Ah-64. It also can be equiped with at-16s (new varients) which are faster, more accurate and is more immune to jamming than the Hellfire missiles. Although the hellfires work better at night thanks to its radar guidance.
Iam not a biased person, i would poke if someone said n011m bars radar is better than apg-77, or a Russian UAV, is better than US or israeli ones, or GLONAS is better than GPS, or AKULA II better than sea wolf. On the other hand i would simply laugh if someone said HArpoon missiles are better than Kh-41, patriot better than s-300/s400, m270 better than bm-30 smerch.