Storm Eagle
The Storm Eagle Assault Gunship is the "middle brother" of Space Marine aerial transports, carrying twenty Marines as opposed to the Stormraven's twelve-plus-Dreadnought or the Thunderhawk's thirty. The Space Marines used loads of them during the Great Crusade, but the forge worlds that made them were destroyed during the Horus Heresy. This meant that the only Storm Eagles in use were those left over at the end of the Heresy, so you had to be from the First or Second Foundings to even have them and they were only seldom deployed, but those chapters who are friends of the Adeptus Mechanicus seem to be using theirs a lot more frequently, almost as if they're being made again...
Given how powerful all Space Marine aerial vehicles are, you'd think that they would make use of as many as they could by flying around empty ones modified for dropping bombs or holding more weapons/ammo to support their brothers on the ground. Or, hey, how about using the fuck-tons of chapter serfs to pilot air craft and drive tanks and shit so all the power armored super-soldiers can do what they do best. Kill shit with bolter and chainsword. Please note that this is exactly what the Legiones (not misspelled, blame Games Workshop) Astartes did and they conquered a million worlds almost single-handedly in about two or three centuries.
It's a Forge World product, created to beef up the Space Marines' section of Imperial Armour Aeronautica (as if the Marines didn't have enough toys already), and to give some non-Apocalypse aerial transport to those Chapters that aren't Blood Angels or Grey Knights (including Chaos Space Marines). It also spots a twin-linked Heavy Bolter, an array of Missile Launchers and four Lascannons.
Clearly effective at killing any enemy vehicles present at a drop-zone and saturating the surrounding area with missiles and heavy bolt shells before deploying is Marines.