Anima: Beyond Fantasy has several (just look at the artwork or the miniatures). Some examples are the "Angelus" used by Abel, the Lawgivers he gave to his followers (one of them, the "Aldebaran", has a mass of 250 kilograms), or Kronen's one.
BattleTech: Starting around 3050, Mechs gained a new melee option in mech sized swords, which further got expanded into experimental Vibroweapons versions later on. Should be noted that except for the aforementioned Vibro weapons, the melee weapons are basically stylized 5 ton metal clubs.
Compared to hatchets, swords have a better hit chance (due to better weapon balance) with a minor drop in potential damage.
The fullblade is a BFS that is larger and more powerful than the regular greatsword, but required an exotic/superior weapon feat to use.
Goliaths, half-giants and users of the Monkey Grip feat can wield weapons made for creatures a size category larger than they are. This might lead to a character wielding a nine-foot bastard sword, one handed. There are also magic items that let you do the same thing. Thank Heaven they don't stack. Too bad they aren't very good.
A Dungeons & Dragons variant, Iron Heroes, allows you to select "Mighty Build" as one of your two Traits for a starting character. This allows you to wield weapons that are one size category larger than you, meaning that your character can wield his or her very own BFS (or whatever other weapon he or she specializes in).
Some fans believe that Japanese adoration of big swords stems from Japanese fantasy fans seeing western D&D miniatures. The miniatures had out-of-scale swords, which weren't a specific statement so much as a way to make the swords easier to see on the models as well as easier to paint. Reportedly, this was interpreted to mean that such a weapon was standard in western-style fantasies.
One of the big feature of Exalted are BFS called Daiklaves. Weapons can be made from one of the five magical metals of the setting (Orichalcum, Moonsilver, Starmetal, Jade and Soulsteel) and then attuned to by the right sort of person. In general the weapon is called an artifact. When the weapon is a sword, it's called a Daiklave.
Noted to be impossible to wield by normal people. Exalts who can 'attune' to the weapon can carry and wield it as if it were lighter than a conventional sword.
Then there are Grand Daiklaves, which are BFS versions of regular Daiklaves. Yes, BFS versions of a BFS.
And the Chainklave, which fuses BFS with Chainsaw Good For Massive Awesome.
Fabula Ultima: The artwork for the Darkblade class depicts a female knight wielding a massive sword. Its blade is about as wide as her torso, and from tip to pommel the weapon is longer than her entire body. The introductory Press Start adventure uses this artwork to represent Lavigne Fallbright, who wields a greatsword as her main weapon.
As a rule every single blade shown in the 40k universe will be much larger than anything in real life. This is both for modeling purposes and rule of cool, and include things such as the Catachan Fangs. Knives that are as long as the model's arms.
Some Priests and the Sisters Repentia of the Adepta Sororitas carry Eviscerators, huge versions of the setting's ubiquitous chainsword. They are said to be able to cut through tank plating—indeed, in game terms they're slightly more effective than meltabombs, which can pulverize tanks as a general rule.
The Aeldari love these things. Large power swords tend to be a common armament for Wraithlords and Wraithknights, and the Avatar of Khaine uses one called "The Wailing Doom", and both can cut through tanks. On a smaller scale, Warlocks and Farseers wield Witchblades, which are quite large in comparison to the the wielders.
The Incubi of the Drukhari carry enormous power swords known as klaives. These blades are as long as their wielder is tall but are perfectly balanced and light enough to be swung one or two-handed.
The Emperor's Champion, a special character who is part of the Black Templar Chapter, wields a sword that, from the pommel of the handle to the tip of the blade, is two feet longer than the Marine carrying it is tall. That's about ten or eleven feet. It is allegedly capable of carving straight through the armour of a Land Raider.
The average Commissar walks around with a chainsword almost as tall as he is.
The Nemesis Dreadknight used by the Grey Knights can wield an immense sword longer than some buildings are tall.
One of the new Space Marine models introduced as part of the rollout for the game's Ninth Edition rules is the Judicar◊, a Primaris Marine wielding an executioner sword almost as long as he is tall...and considering Primaris Marines stand around a head taller than standard Astartes, that makes for one huge sword.
In the 1st and 2nd Editions of Necromunda, two-handed swords as large as those that wielded them were available but rarely saw much use as the combat system generally favoured using multiple smaller weapons rather than a single, slow and heavy blade.
There are a lot of weapons in Warhammer Fantasy that fit into this trope as well. The Empire, for example, have an infantry unit called Greatswords. Ogre Ironguts have a spear large enough that a normal human could conceivably ram it up a Giant's nose while lying down, and the Kroxigor's weapons were described on the Warhammer page as being "trees with blades on the end."
One sample Mekton Mecha Manual robot was designed to absorb enemy energy weapons fire, to power an upgrade from its normal Laser Blade to a humongous one known as the Atomsplitter Sword. It makes a kickass Finishing Move.
Steve Jackson's card game Munchkin (illustrated by John Kovalic) features characters wielding weapons (including swords) of improbably immense size.
The Big Honking Sword of Character Whupping. No, you can't take it for yourself, nice try.
The Sledgehammer of Smackdown, with a head significantly larger than the person holding it.
The similarly over-sized Unnatural Axe.
The Neopets card game parodies this with the card "Big, Heavy Sword" which depicts an Usul (unsuccessfully) trying to wield it.
Dungeons & Dragons variant Pathfinder has an iconic barbarian as an NPC called Amiri. She wields a giant-sized bastard sword which was taken off a dead frost giant. In something of a subversion, she has a bit of trouble wielding the thing normally because it's so big, and can only fully wield it when she is in the throes of her blood rage.
A scene in the Great Pendragon Campaign has a BFS which isn't actually used in battle but is a bridge, similar to the example in Arthurian Legend on which the game is based.
Shadowrun features claymores as available melee weapons; outstripping katanas in terms of reach, damage, and armor penetration, they're less accurate, and significantly more restricted, expensive, and conspicuous. The Highlands Forge Claymore is noted to be designed for larger metahumans such as orks and trolls, and it's noted that if you aren't a troll, then the blade is too long to draw from an ordinary sheath, requiring a quickdraw sheath to make it viable.
Stormwild Islands has the Colossal Sword, which has the highest base damage of all melee weapons. It's so big that it deals blunt damage instead of cut damage, and only those invested in the Brutalism combat skill can wield it.
Spycraft 2.0 has a sword weighing 30 lb that ostensibly represents a zweihänder, which in reality weighed less than a quarter of that — an actual sword this heavy would resemble Cloud's Buster Sword more than any real weapon and be completely impractical in any setting pretending to be at all realistic.
Elemental Hero Wildheart, who wields a sword that would measure from the top of his head to his shins, were it held vertically. By fusing him with Elemental Hero Bladedge, however, you get Elemental Hero Wildedge. Just the visible part of his sword looks to be almost as tall as he is, but it's cut off by the card frame. It looks to be quite a bit longer, though. The kicker? The hilt is clearly too small for him to wield it with two hands.
Seismic Crasher carries two of these, one green and one purple, representing his power to sacrifice a Spell or Trap card up to twice per turn to deal damage.
In fact, Bladedge himself IS a BFS. That, or his costume is one — depends on whether he's a guy in a costume, or a robot.
It is however inverted with Defender, the Magical Knight and his, well, it would be generous to call that thing a "knife". Although, as the name suggests, he makes up for it with a Big Freaking Shield.
Taken to ridiculous levels with Super Quantal Mech Sword — Magnaslayer. It's a giant Laser Blade designed to be wielded by a Humongous Mecha, whose blade is roughly as long as the mecha is tall.
◊, a Primaris Marine wielding an executioner sword almost as long as he is tall...and considering Primaris Marines stand around a head taller than standard Astartes, that makes for one huge sword.
