Helicopter
Buttkicker
If you've been on the fence about getting a BK for FS2, then the R-22 should make that a very easy decision. That low frequency rotor thumping + VR will be very immersive! I've had mine for almost a year and I always notice when I forget to turn it on - it's great with planes but should be even better with helicopters.
Also, I just checked the BK site and they have a 25% OFF coupon code "THANKS2018" that is good through Dec 2nd so you can get a BK2 for $130 (US).