The military backbone of the Empire, the Stormtroopers were what kept it going. They never did manage to hit anyone though. Here are some Bizarre stormtrooper variants for you.
The Terror Troopers were inspired by General Grievous, One of the founding fathers of the Galactic Empire. The Troopers were actually cyborgs. The Imperial Department of Military Research created the Terror Troopers to act as espionage and assassination operatives. They are tasked with going behind enemy lines and conducting suicide missions. When the Rebel Alliance was formed. Darth Vader personally dispatched a contingent of Terror Troopers to track down Juno Eclipse.
The Inquisitor Troopers are actually Republic era Clone Troopers that were radicalized. They were manipulated by Emperor Palpatine into becoming a fanatical death squad. The last batch of Kamino Clones were used to hunt down all the Jedi that had escaped Order 66. The Inquisitors were programmed to kill all Jedi on command. Padawan Barr used this to take down his enemies, the Inquisitor Troopers were turned on their Inquisitorious masters, who once used to be Jedi.
In the Galaxy far, far away, life can spring up in the harshest of environments. Where there was life, there was bound to be descent. It was the job of the Empire to subdue any world, no matter how harsh, if it fell out of line. EVO Troopers or Environmental Troopers came equipped with heavy breathing apparatus and custom armor. They underwent special training and were given heavy weaponry to decimate hostiles in environments of extreme heat and cold, acid rivers, and lightning.
Riot Control Troopers
Riot Control Troopers had a more specialized, niche role. Their only job was to maintain law and order in First Order controlled worlds. They are trained in using non lethal weaponry like Betaplast Ballistic Riot Shields, and the powerful Z6 Riot Control Batons. If push comes to shove, they can also use blaster pistols and rifles to subdue the populace. They were seen last in Star Wars: The Last Jedi.
The Purge Trooper was an early attempt by the Empire to create a Force Resistant Droid to fight the Jedi. The Stormtrooper is actually a robot. Fit with a deadly energy blade and rocket launchers, it was a force to be reckoned with. Purge Troopers could also generate a powerful red force field. Even a powerful Force push was not enough to push them back. They are later deemed a failure because of their vulnerability to Force Lightning.
When Star Wars was still in its nascent stages, George Lucas wanted every Stormtrooper to be equipped with their own lightsabers. Obviously the idea was dropped. a Lightsaber is a weapon of elegance. It should only be given to those trained in the art of Jedi warfare. Dark Jedi Desann and Admiral Galak Fyarr created a Stormtrooper variant clad in black lightsaber proof ‘Cortosis’ armor. They had unique synthetic crystals in their armor that allowed them to use the Force as long as they remained in the vicinity of Dark Side of the Force.