I don't see how the Kerambit wouldn't be counted as "cool"
No matter, here's a "modernized" Browning M2HB equipped with SureFire's Hellfighter 4 High Beam weapon light.
Also an interesting AR-15 accessory by KNS Precision, a stock adapter that turns into a "spade grip" much like crew mounted MGs like the M2HB above. The purpose is so that it can be used as a mounted weapon(don't see why you'd use an AR-15 for that though) which KNS also has a tripod mount for the AR-15. Image below features both.