VF-1 Veritech "Valkyrie"
The VF-1 was the Robotech Design Team's solution to the question of how humans could fight 40 foot tall soldiers. It was fine to engage them with powerful weapons from the air, or tank like vehicles. But sooner or later, hand-to-hand combat would be required. And that was the purpose of the VF-1.
The Veritech Fighter had the unique ability to transform from a jet fighter into a humanoid form, known as a battloid. This actually arose from the human misunderstanding of Protoculture. The basic properties of this new power source seemed to encourage such modularity, although no other species, including the highly knowledgable Robotech Masters, ever used this in thier combat mecha.
However, it produced a mecha of unparalleled maneuverability and funcionality. It could race over a ground target at Mach 3, strafing with missiles and machine guns, then convert to a ground unit and mop up, secure the area, etc.
It also has a third mode, Guardian, that was not part of the initial design. This is sort of a transitional phase between Fighter and Battloid. It was initially only planned to be used for VTOL landings and rapid deceleration. However, test pilots quickly learned to use this useful mode in combat, allowing instant changes of direction, height and speed. And with the GU-11 gun point in the jet's hand, they could even fly in one direction, and shoot in another!
There are 4 models of the Valkyrie, the VF-1A, VF-1J, VF-1S and VF-1D. The A, J, and S are all single seat fighters, and identical in all aspects except number of head lasers. The VF-1D however, is a two-seat trainer, but still fully combat capable.
Also, due to thier protoculture-powered engines, Veritechs can operate at full capacity in space. One other point to note is that in Battloid mode, the mecha has agility beyond anything the average human is capable of. Any moves that the pilot can do, the mecha can easily copy, including martial arts attacks.