Sky Hunter Squad
Sky Hunters were specialized fast-attack Space Marines used during the Great Crusade and Horus Heresy and was considered as a step-up when compared to the Legion Outrider Squad.
Overview
Mounted on Imperial Jetbikes, Sky Hunters were feared strike units boasting considerable firepower on their mounts in addition to their superb speed and manoeuvring capabilities. The Jetbike patterns in service with the Sky Hunter Squadrons of the Legiones Astartes are modifications of designs which considerably predated the Imperium and given the materials required to make and maintain them (such as iridium-calicite alloys and repulsor plates), demand for them by the Legions has largely been outstripped. So much so that sometime after the Heresy, Sky Hunter squadrons largely ceased to exist.
Sky Hunters themselves typically operated in squadrons of three, each led by a Space Marine Sergeant. Their Jetbikes, often Scimitar and Bullocks pattern craft, sported a mixture of Heavy Bolters, Multi-Meltas, Volkite Culverins, and Plasma Cannons.
Crunch
The famed Dickbikes. 3-10 strong, 1 in 3 can replace Dickbike Jetbike mounted heavy bolter with multi-melta, volkite cannon or plasma cannon options, they can buy melta bombs and they can Deep strike, but only the sergeant can buy a power weapon (while he's technically an upgrade, he's practically an auto-include, improving your melee punch and giving an extra point of Ld to save your fairly expensive squad). Very high mobility coupled with T5 and a 2+ save with Heavy weapons makes for a very powerful combination. Aim them at the enemy's vagina/anus and let them fly.