All giant robots are just not built the same. Some mechas tower over your city, while others just sort of tower over your garage. When the fate of the world depends on giant robots smashing each other — as it so often does — you want a giant robot that's really giant. Luckily, we've got you covered with our run-down of which giant robots actually deliver on the "giant" part of the equation. We already covered the tallest giant monsters, but it's important to recognize the robots that measure up in the height department as well. The fate of the civilized mecha-world could depend on it! So here goes:

Gigantor, from Gigantor Who is he: In the American version of anime/manga series Tetsujin 28-go, it's the year 2000, and Gigantor is the flying robot companion of Jimmy Sparks, who helps Jimmy fight crime. How tall: Three storeys, or about 10 meters. I think Gigantor needs a new name.

Robosaurus, the real-life robot. Who is he: The first "car-nivorous" robot, Robosaurus travels around causing fiery mayhem at car shows. How tall: 42 Feet, or about 12.8 meters. Imperial AT-AT Walkers, Star Wars Who are they: The big stompy robo-elephants that smush the rebels at their base on the ice planet Hoth. How tall: 15 meters, according to

Killer robots, Sky Captain and the World of Tomorrow Who are they: These giant robots attack the city in this alternate version of 1939, leaving Joe Sullivan aka Sky Captain to save the day. They're supposedly based loosely on Max Fleischer's designs from his Superman cartoon "Mechanical Monsters." How tall: About five storeys, or around 15 meters. The Tri-Sentinel, Amazing Spider-Man Who is he: Ummm... it's complicated. These giant robots, the Sentinels, were built to hunt down and kill the mutants, including the X-Men. But the trickster god Loki merged three of them into a single massive robot, programmed to destroy the nearest nuclear power plant. Luckily, Spider-Man had cosmic powers at the time. Yes, comics are confusing. How tall: 60 feet, or about 18.3 meters.

The Iron Giant, from The Iron Giant Who is he: Based on the classic Ted Hughes children book, this is the story of a giant robot who crashlands in a small town and befriends a little kid. The U.S. Army is searching for the robot, and in the end their confrontation gets escalated into a nuclear attack. How tall: 50 Feet, or about 15.24 meters. And here's the tearjerker ending:

Megatron, Transformers Who is he: The leader of the Decepticons, the evil transforming robots from the planet Cybertron. Megatron fights against Optimus Prime, leader of the good Autobots, who come to Earth seeking the Allspark. How tall: 51.7 feet, or about 15.76 meters.

Tranzor Z, Mazinger Z Who is he: Constructed of a new kind of metal called Japanium, found only near Mount Fuji, this giant robot was created by Go Nagai. Known variously as Mazinger Z and Trantor Z, this robot is regarded as the first piloted giant robot in history. How tall: 18 meters.

Kronos, Kronos: Ravager of Planets Who is he: A weirdly abstract giant robot vampire that feeds off energy and eats H-bombs for breakfast. How tall: 100 feet, or about 30.5 meters.

Mechagodzilla, Godzilla Who is he: Created by "black hole aliens," this was a giant robot version of Godzilla, disguised as the real thing. Luckily, the real Godzilla showed up to battle his chrome pretender. How tall: 50 meters

Shin-Getter 1, Getter Robo Who is he: Another awesome Go Nagai creation, he is the ultimate Getter. He's made up of three jet-like vehicles, piloted by separate pilots. There's a red jet, a yellow jet and a white jet. How tall: 55 meters GoLion, Beast King GoLion Who is he: One of the giant robot stories that became the lion version of Voltron in the U.S., GoLion features an arrogant beast robot who gets split into five different lion robots that crashed on the planet Altea. A group of five human pilots find the robots and unite them into GoLion to fight the evil Galra Empire. How tall: 60 meters Dariugger XV, Kikou Kantai Dairugger XV Who is he: The "Vehicle" version of Voltron. Originally he was just an exploration robot as well as a peace-keeping force. Dairugger is launched to defend the Earth from the Galbeston Empire. How tall: 60 meters Supertrain Megazord, Power Rangers Who is he: When the Rangers' awesome five "Rescue Rails" join together in an emergency, they can form the Supertrain Megazord, an incredibly powerful giant robot whose only weakness is Congress cutting funding for Amtrak. (The "Megazord" thing refers to the fact that the trains each contain one of the "Omega Zords." Make sense now?) How tall: 80 Meters And here he is in action:

SDF-1, Macross/Robotech Who is he: Also known as Super Dimensional Fortress One, this is the reconstructed spaceship of Zor, the founder of Robotechnology. It crash-landed on Earth and the humans rebuilt it and re-launched it just in time for the alien Zentraedi to arrive and invade. How tall: 1210 meters. Unicron, Transformers Who is he: Known as the "chaos bringer," Unicron dates from the beginning of the universe. The biggest and most deadly of the Transformers, he aims to absorb the entire universe, planet by planet. And he has the voice of Orson Welles. Basically, unbeatable. How tall: Planet-sized, with a diameter of to 1,000 kilometers. There's really no competition at all. But don't take my word for it. Here's Unicron speaking for himself. Don't understimate him, yo.

Reporting by Katharine Duckett.