An old comic book ad for AAU Shoes had their superhero spokesman the AAU Shuperstar battle a villain called Missile-Toe who fired missiles from his toes. Check it out here.
Anime & Manga
Sanji in One Piece is an Extremity Extremist who uses only his feet in battle. The second One Piece movie saw Sanji's shoes stolen, and Sanji unable to fight properly as they provided added protection for his feet. (He learned this from his mentor, Zeff, who was known as "Red-Leg" when he was a pirate; Zeff only used kicks in a fight, which often ended with his boots covered with the blood of his foes, which is how he got his nickname.)
He justifies choosing this style as having his hands bruised or calloused from fights would affect his performance as a cook. Though ironically he is still a chain smoker.
Mazinger Z: Mazinger-Z had one rocket on each foot. They were intended to allow it swim, but Kouji also used them like weapons -usually blasting a Mechanical Beast's face to force it to release Mazinger-Z). Several Mechanical Beasts also had weapons fitted on their legs (for example, Deviler X1 had a rocket launcher!).
Great Mazinger has two attacks based around this, the Knee Impulse Kick (a retractable knee spike) and the Backspin Kick (a cutting blade in the lower leg).
Infinite Justice from Mobile Suit Gundam SEED Destiny has beam emitters that generate a cutting edge from knee to ankle giving it a rather nasty kick. Its distant ancestor the Aegis had beam sabers on all four limbs since it could transform into a claw-like flight mode. The unrelated Chaos Gundam from Destiny has beam claws in its feet and knees, mainly used in its flight mode.
The 105 Slaughter Dagger from Gundam SEED CE 73 Stargazer has machineguns in its feet. This seems unusual until you see episode 2 and discover (the hard way) that they're anti-personnel guns.
After its first round of modifications the Blue Frame in Mobile Suit Gundam SEED Astray has a pair of "Armor Schneider" blades that pop out of the unit's feet and heels.
The titular Crossbone Gundams have Anti MS knives concealed in the calves, with the blade able to pop out through the sole of each foot.
Then there's the Arche Gundam, which has beam sabers mounted at the tip of its feet.
On the heroes' side, the Seravee Gundam has GN Cannons whereas other Mobile Suits have kneecaps. Taking this trope literally, they also mount "hidden hands" which can wield beam sabers.
Its successor in the Movie, Seravee II is even better. Its feet are Detachable GN Cannons while it is docked on Raphael.
Speaking of rollerblades, pretty much everyone in Air Gear, but Nike takes it Up to Eleven by creating blades on his legs
Vash of Trigun has a pair of blades hidden in his boots that seemingly spring forth from a hard step.
The Type 17 Raiden and Type 17I Shinden in Gasaraki have a pair of pneumatic spikes mounted in each leg, one firing downward through the calf and the other upwards through the knee; admittedly, they're meant for making holes in concrete walls and floors, but they often see improvised use against other TA's, taking kneeing someone in the gut and curb stomping to new heights.
Straight Cougar from s-CRY-ed can manifest his Alter as a pair of rocket boots and use them to make "bullet" attacks similar to Kazuma's.
The Gurren-Lagann is capable of creating 3 Giga Drills on each knee-cap. As well as one on each leg to replace the lower legs.
It is also able to make perform a "Gurren-Lagann Impact!" as shown when they combine with Arc-Gurren... By transforming the lower half of Gurren-Lagann into a giant drill and actually Giga Drill Breaking the Arc-Gurren from up front. All their allies think Simon and Viral are against the Dai-Gurren-Dan.
Chouginga Gurren-Lagann (AKA Super-Galaxy Gurren-Lagann in English). It is capable of creating Chouginga Giga Drills wherever it wants to. And then it can create more drills on those drills. And more on the second layer of drills. And then to top it off, it can create small, drill-shaped laser cannons that can target the enemy not just anywhere, but also anywhen. Yes. The Time-Space continuum can go die in a fire when Chouginga Gurren-Lagann shows up.
The titular mech, Tengen Toppa Gurren-Lagann (meaning Heaven-Piercing Gurren-Lagann). It has 30 Probability Fluctuation Missiles in each shin. That means a total of 60 Missiles that can alter Probability itself. The same goes for the Tengen Toppa Dai-Gurren in the second movie.
In Buso Renkin the female lead has a very pragmatic reason for wearing a short skirt... when she summons her weapon, the Valkyrie Skirt, it appears as scythe-bladed "spider legs" that are worn via metal bands at mid-thigh.
In Bubblegum Crisis, Priss' Powered Armor has contact-triggered explosives on top of both its feet. And rockets on both ankles. Attack sequence; 1). Jump. 2). Kick. 3). Activate rockets for rocket assisted kick. 4). Explosives go off once Mecha-Mook receives kick to head. 5). Get dustpan to sweep up remains of mook.
Gunsmith Cats has Bonnie from the early stories who got blown up by Minnie. She replaces her lost leg with a prosthesis outfitted with a shotgun. The 3 part OVA gives a Continuity Nod to this when one of the two exotic weapons Washington offers to Rally ends up as this (the other one is Grey's machete prosthesis from later stories).
Black★Rock Shooter gives us a few examples from its stable of characters. Most notable are Chariot (sports bionic-looking legwear that ends in a razor-toothed wheel on each leg), and the illustration-only Black Rock Shooter Beast, who has small energy buzzsaws on the toes of her shoes, and some kind of articulated scythe-limbs on the backs of her shins.
Iron Man has repulsors in his boots, that let him fly as a rocket. They are not meant to be weapons, but can be used as such: if he's in the ground, and the enemy is in the right direction, he may turn on his foot rockets at his face. It's not nice.
Marvel villain Tarantula, who usually fought Spider-Man, had as his main weapon spikes protruding from the toes of his boots; these could be used simply for slashing or stabbing, or to poison/drug an adversary.
Stompa of the Female Furies wears anti-matter that she uses to crush her opponents and which can create tremors or earthquakes by stomping on the ground.
Marvel Universe villain Stilt Man wears a set of weaponized extendable metal stilts.
When Sakura joins the TSAB in Devil Ärms: ReturnerS, her Intelligent Device, Sound Harken, takes the form of a pair of ice skates, the blades of which constitute her main weapon. They can also be used to grind on the chains created by her Armed Device, Rivet Rail.
Played for laughs with Random Task of Austin Powers, who throws his shoes like a certainJames Bond villain throws his hat. "Who throws a shoe? Honestly!"
In Tim Burton's Batman, towards the climax Batman faces one of the Joker's mooks, who attempts to drop-kick him while blades extend from his boots. Batman instead simply punches him in the nuts and moves on.
Big Trouble in Little China: Jack Burton keeps a knife in the straps at the side of his boot. Normally this is just for storage, but at one point, he kicks it down into a Mook who is on top of him. It works rather too fast and he's sidelined for a while by the body's weight.
In Road House, one of Brad Wesley's goons has a blade hidden in the toe of his boot that he tries to use on Dalton. Alas, the goon proves to be "too stupid to have a good time," and so Dalton easily defeats him anyway.
Phillip Stryver: Do those heels make it hard to walk? Catwoman: (stamps heel through Stryver's foot) I don't know, do they?
In the Gentleman Bastard Sequence, Capa Barsavi's daughter Nazca, at the age of seven, demanded a pair of boots with iron spikes on the toes so she could enact the Little Girls Kick Shins trope more effectively.
Played very practically by Adora Belle Dearheart in Going Postal. She isn't an Action Girl, but as she calmly points out, being stepped on by stiletto heels is like "being stepped on by a very pointy elephant" due to the sheer amount of pressure concentrated in one heel point. Possibly a stealth pun, given that this is the design philosophy behind actual stilettos of the non-footwear variety. By focusing the full force and weight of your body behind a small enough point, they could be fairly easily driven through even well-crafted chain armor.
In the Elenium, queen Ehlana's bodyguard Mirtai has managed to embed daggers into her boots so that only the tips emerge, making them mostly inconspicuous unless she happens to kick someone… especially where she prefers to kick them. She also had blades built into her leg armor that protruded out when she bent her knee.
Live Action TV
Canadian comedy troupe The Frantics have their famous "Boot To The Head" sketches.
Kamen Rider has a few characters do this, given that the franchise's signature finisher is a kick attack. Examples include Kamen Rider Kiva's 'Wake Up Fever', and Kamen Rider OOO's Condor and Wani legs. Special mention goes to Kamen Rider Fourze, who, due to his module system, has a choice of about ten attachments for each leg, many of them weapons such as a chainsaw, gatling gun or missile launcher. His finisher uses his favorite- a drill equipped to his left leg.
Jethro on The Beverly Hillbillies rigged up a boot to extend a blade, which he immediately managed to get stuck in some furniture.
Jake Crist wrapped barbed wire around his leg and delivered a super kick to CZW's bad boss DJ Hyde, whipping him across the face with it as the impact knocked Hyde over.
Black★Rock Shooter Beast's Figma accurately reproduces the leg-scythes and feet-buzzsaws mentioned above.
In Space 1889 there is one of the few times this trope is justified. The flying High Martians carry close combat weapons (that do not really correspond to any weapons humans use with their hands but mostly resembles spears or scythes) in their prehensile feet while using their webbed arms for flying. You can see it in the illustration in the background in the Space 1889 article.
4Chan in their /tg/ board has the homebrew Space Marine chapter Angry Marines (ALWAYS ANGRY! ALL THE TIME!) who have Power Feet. They are the shoe version of the Power Fist. And like the Fist, they're freaking huge metal cyborg-exoskeleton armored boots that can't be lifted by ordinary feet. Only those of sufficient constant rage can properly use them.
In Age of Aquarius Second Edition, a number of heavy footwear increases your character's kick damage and lets it deal lethal, not subdual wounds. These include combat boots, Russian army jackboots, safety boots, Grinders and Dr. Martens. The first edition lacks subdual damage mechanics and only has the army jackboots in the weapon table.
In Exalted , artifact weapons are not called by the same names as their mundane equivalents. Swords are called daiklaives, spears are called direlances. And then there is a type of artifact weapon called "God-Kicking Boots".
The Forgotten Realms setting has blade boots as a weapon (think From Russia with Love, above). The boots can be used to attack, in exchange for not being able to run with the blade extended.
Most practical BattleMech melee weapons in BattleTech are, as one would expect, arm-mounted. The big exception are talons, about the one melee weapon system originating with the Clans who normally disdain close combat in 'Mechs — these are instead added to the legs and increase the damage of kick and death-from-above attacks by 50%. (Some 'Mechs will also carry leg-mounted conventional weapons, but those generally fall more under the Leg Cannon trope.)
Regal in Tales of Symphonia, owing to the fact that his hands are bound for most of the game. He continues to use his greaves in the sequel even after he removes his handcuffs, after vowing never again to use his hands as weapons of death. He takes his vow literally, as he won't hesitate on using his feet to kill (including a man who was beyond salvation along with Presea).
Chie in Persona 4, despite the fact that most of her weapons are not metal, they are still bought from a metal smith.
Duster from Mother 3 fights with kicks and thus needs shoes.
Duster has a club foot (which is why he limps), so the extra-thick soles provide more buttkicking power.
Also played with in Earthbound after fighting the Kraken; the captain claims to have thrown his slippers at the monster as they fought.
Dante in Devil May Cry wields these with his Beowulf weapon. It returns in the form of Gilgamesh in Devil May Cry 4.
Charge Man's weapon, the Charge Kick, from Mega Man 5. More specifically, it weaponizes the slide.
With Loads and Loads of Characters, it was only natural to have at least one entry from the Suikoden series fight with their feet. In this case, it's Wakaba, whose "Shin Guards" can actually be improved by a blacksmith as the game progresses; presumably, her Armed Legs add to her fierce, Chun-Li-style kicks.
One of Hinata's special moves in Rival Schools is kicking her shoes at the enemy from midair, complete with pretty rainbow trail effects.
Kisala's secondary weapons in Rogue Galaxy are shoes as well.
Used interestingly in Bayonetta: the title character is capable of quadruple-wielding guns by virtue of strapping a pair to her heels. The result is a very literal example of Combat Stilettos. Also by attaching other weapons to her feet, such as shotguns, ice skates, fire/electricity energy claws, and a pair of rocket launchers. One of these days, these boots are gonna walk all over you.
Gale from Digital Devil Saga keeps a concealed blade in his shoe which extends when he kicks. He only ever uses it in cutscenes, as when he fights in human form, he uses his assault rifle instead. Appropriately, in his devil form, he attacks with his feet exclusively for physical attacks.
The Takewown class in Ragnarok Online uses kicks, but they don't use boots as weapons. Only their upgraded version can actually even equip a weapon (Books)
To some degree, M. Bison of Street Fighter II uses this. His metal greaves are one of his most distinct traits and his kicks do tend to be Muay Thai-style shin kicks that would seemingly employ them.
The Grieve Edge fighting style in Soul Calibur consists entirely of kicking with bladed feet.
Metal FatigueCombots could roll out of the assembly bay packing light artillery, missiles pods, or lasers mounted on their legs. Armed Legs are the earliest leg research options available.
Variant in Metal Gear Solid 4 and Metal Gear Rising: Revengeance. Raiden's cyborg body doesn't have any weapons in it's legs, but he has rubberized heels that allow him to grip knives and swords with his feet. Most of his stronger slices are executed with his feet.
Mavado uses these during one of his fatalities in Mortal Kombat: Deadly Alliance.
The Bouncer class from Phantasy Star Online 2 wields Jet Boots as one of their main weapons. They're not actual boots per se; they're a bladed attachment to your feet that allow you to Double Jump, float in midair while casting a Technic, and perform some crazy acrobatic kicking while dropping a buff or two at the same time.
Tikedi in Prophecy Of The Circle use metal claws strapped to their feet in their hunting routine for chasing tekk, a much bigger reptilian/avian species.
Tagon in Schlock Mercenary has Dorothy Wire in his boot heels, so named because the user clicks their heels together to activate it. Only used a few times due to the rather limited utility (it's only effective against things you can get between your feet), but it makes for a handy surprise in those rare instances that it is practical.
The Bronze Kneecap from The Fairly OddParents conceals a multitude of weapons in his prosthetic knee, the most famous being a small rocket launcher.
In Star Wars: Clone Wars, General Grievous can wield lightsabers with both feet, so long as he uses his arms for support. In a battle, he's agile enough to switch from using them with his hands, to feet, and back to hands within seconds. Even unarmed, his feet are clawed, and capable of crushing metal. (Or clinging to the side of a spaceship, seeing as he's a cyborg and can apparently survive in the vacuum of space for at least for a little while.)
Real life example: Near the end of George W. Bush's term, an Iraqi reporter threw his shoes at him, considered the ultimate insult in Arabian culture. Bush ducked, though. Makers of Political Cartoons were overjoyed, as the incident provided a handy visual metaphor for anything for the next few months. Bush's handling of it was great, though. "It was a size 10".
Steel-toed boots were created to prevent dropped objects from crushing workers' feet. It was soon discovered that they come in handy for kicking as well.
Steel-toed boots with a small blade concealed in front have been used as weapons by some lesser gangsters, under the supposition that a powerful kick may disembowel the opponent. However, to be able to walk in the first place, the blade has to be very short and handheld knives are more effective.
Velociraptor, Deinonychus, and other raptor-type dinosaurs with a huge sickle-claw on each foot.