So uh, yeah, this is my dream team that's gonna save the Earth. Welp, here it goes:
Welkin Gunther (Valkyria Chronicles)
This badass TANK COMMANDER lacks nothing in leadership nor battle tactics. With this man's wits to tread through even the most risky operations (along with the strategies to do so successfully), this team is more than likely to fight off the Earth's threat and survive. Also his tank is very well armoured.
First Round Pick:
Terminator (The Terminator)
"That Terminator is out there! It can't be bargained with. It can't be reasoned with It doesn't feel pity, or remorse, or fear. And it absolutely will not stop, ever, until you are DEAD!" - Kyle Reese (The Terminator)
The name says it all. It terminates things. It is a machine that will stop at nothing until its mission is complete. In this case, programmed to eliminate Earth's invaders and listen to Welkin's orders, it is a perfect ally in this squad. Super human strength, infinite endurance, and persistence make up the basis of this machine's capacity to do its job (not to mention guns, and a whole lot of them).
Second Round Pick:
Samus Aran (Metroid)
AKA space bounty hunter that's hunted and killed other space bounty hunters. She has tons of experience in group military missions and even more and lone-wolf missions of her own. If there is a queen of space, it's her, her power suit contains missiles, freeze beams, wave beams (passing through walls) and small power bombs that emit bursts of nuclear energy that vaporize anything within range (basically mini nukes). Not to mention her ability to literally jumping and keep jumping in mid-air (space jump). Even without her power suit, she is still near-unstoppable in terms of combat. With her energy whip, stun pistol, jet boots, and super-human reflexes, she is the Kill Bill of space.
Third Round Pick:
Kei Kurono (Gantz)
This guy has been to hell and back countless times, AND actually saved the Earth once already. He may not be professionally trained in any actual martial art or combat, but he's already trained himself with his experience within Gantz. His suit gives him super-human strength, speed and endurance. His gun literally blows anything up from the inside out, and his sword slices through literally anything (if only he new the proper way to use it). He has the resolve and persistence to survive anything, and he will stop at nothing to save Earth once again.