Anti-Berserkers
You have probably sent this card off of Dragon Ravine at some point.
Absorouter Dragon
One of the most infamous cards of all time, this card drastically increased both the power level and the cost of playing Yu-Gi-Oh the instant it was released.
Dark Armed Dragon
If this card is sent to the GY: You can make all monsters your opponent currently controls lose 300 ATK for each Monster Type you control, until the end of this turn.
Tri-Brigade Rugal the Silver Sheller
The Ballad of the Encounter with the Magnificent Spectral Resplended - Shiranui Story Saga
Ghost Meets Girl - A Shiranui's Story
This is a Synchro Monster often played in Edison decks that can have both Level 3 tuners and Gravekeeper packages.
Arcanite Magician
This card is named after a technical term in music and other art forms meaning improvisation.
Ad Libitum of Despia
This is the only vanilla monster with 2800 ATK and 1000 DEF
Metaphys Armed Dragon
This card gains 200 ATK for each material attached to it.
Downerd Magician
Drochshuile the Dead Spirit King
Due to its attribute and attack stat, this was one of the less bad early Gemini monsters. This card was occasionally played in Gemini Spark decks.
Crusader of Endymion
If not for its low stats, this Fusion Monster would be extremely difficult to out while putting your opponent on an 8-turn clock.
This card can attack twice and inflict piercing. However, it can only do this if it was tribute summoned, and the archetype it belongs to will often summon it by other means.
Qliphort Shell
While this card has a material attached that was originally WATER, it cannot be destroyed by battle.
Cat Shark
Landmine Spider
Jirai Gumo
In terms of the number of cards it can allow you to draw, this is one of the most powerful of all draw spells.
Arcane Barrier
This is a relative of one of the most popular fusion monsters of edison format. It was playable for a time, but Master Rule 5 effectively nerfed it.
A deck built around this card is listed as viable on goatformat.com. It's too difficult to summon to be truly competitive, but if you can make it work, it's Imperial Order on legs.
Silent Swordsman LV7
If you would Tribute a monster(s) for a Tribute Summon, you can Tribute a Zombie monster(s) your opponent controls, even though you do not control them.
Vampire Sucker
Fiend Roar Deity Legion
This was the first Tribute monster in the TCG to use Spell Counters.
This card is a retrain of one of the better McDonald's promos.
Cosmo Brain
This is one of the very few cards with an effect that activates in the opponent's draw phase before they draw.
Diabolos, King of the Abyss
For this card's Link Summon, you can only use monsters in your Main Monster Zone as material.
Scareclaw Light-Heart
Sacrifice
Relinquished
This card is a worse version of Breaker the Magical Warrior. It is used by Rare Hunter, but in the anime it never uses its effect.
Hannibal Necromancer