Darth Sidious/Palpatine x OBD
The most powerful Sith Lord

Name: Darth Sidious, Palpatine
Origin: Star Wars
Gender: Male
Classification: Human Force User/Dark Lord of the Sith/Supreme Chancellor of the (Old) Galactic Republic/Emperor of the Galactic Empire
Age: 50 | 63 | 86 | 93
Powers and Abilities: Superhuman strength, speed, durabilityenhanced senses, various lightsaber combat skills, skilled swordsman, precognition, telekinesis, telepathy, mind manipulation, illusion creation, psychometry, barrier creation (in the form of Force Barrier), energy manipulation (can reflect, redirect, and absorb energy attacks thrown at him), absorption (in the form of Force Drain), elemental maipulation (in the form of Force Lightning and Force Maelstrom), regeneration (mid-low; in the form of Force Healing), technopathy (in the form of Ionize), possession (in the form of Transfer Essence), immortality (type 6), poison resistance, matter manipulation on a subatomic scale (as per editing the Telos Holocron, it requires one to make numerous precision alterations to it on a subatomic scale), Convection, Force Stealth, Force Storm, Midi-chlorian Manipulation, Pyrokinesis, Sith Alchemy, Sith Sorcery
Weaknesses: Overconfidence (as pointed out by Luke)
Destructive Capacity: Moon level (was powerful enough that Mother Talzin made note of his power while her fellow Nightsisters were put on guard, indicating he's not terribly weaker than his counterpart from Revenge of the Sith) | Moon level+ (cited as being the most powerful Sith Lord by various sources, thus should at least be as powerful as Vitiate) | Moon level+ | At least moon level+ (his Force Storms are capable of razing planets and wrecking large fleets of massive Star Ships)
Range: Galactic
Speed: Relativistic+; FTL+ reactions augmented by precognition
Durability: Peak human level+ naturally; moon level with Force amplification | Peak human level+ naturally; moon level+ with Force amplification (survived the backlash caused by his Force Lightning overloading Yoda's Tutaminis) | Peak human level+ naturally; moon level+ with Force amplification | Peak human level+ naturally; at least moon level+ with Force amplification
Lifting Strength: Peak human+; can be augmented to superhuman levels thanks to Force amplification
Striking Strength: Class GJ+ with Force amplification (capable of trading blows with Mace Windu)
Stamina: Superhuman+
Standard Equipment: His two lightsabers
Intelligence: A genius: a master of political and psychological manipulation, orchestrated a galaxy spanning conflict as a means to gain absolute power (along with the gratitude and love of the galaxy's people) in the Galactic Republic through the Clone Wars. Used various brush-fire wars, conflicts and various organizations and other situations through decades of scheming to become the undisputed ruler of the galaxy. Easily manipulates and tricks even other masters of political subterfuge such as Prince of the Fallen, Darth Tyranus and the leaders of the Old Republic.
Notable Attacks/Techniques: 

- Convection: A concentration of Force energy that can make Darth Sidious' fists hot to the touch, even to the point of possessing a burning intensity.  It doesn't inflict harm upon the user.  Darth Sidious has demonstrated the capacity to heat up objects other than himself.

- Force Barrier: Both an offensive and defensive Force power that creates a barrier or wall of Force energy around the intended target, be it self, friend, or foe.   Depending on the strength of the individual, the barrier could only withstand a few attacks before collapsing.

- Force Drain: Darth Sidious drains the life from his opponents and adds it to his own.  He most famously demonstrates this power by using it continuously on the entire population of Byss.

- Force Healing:  Accelerates the body's natural healing process at a rapid pace.  Master practitioners of the art can even heal themselves from fatal injuries in a short span of time.  Darth Sidious could use this power to heal himself and others.

Force Lightning: An offensive Force technique that uses Force energy to produce electricity with one or two hands that stream outwards from the fingertips, its speed is usually great enough to catch an opponent off-guard even when prepared, and can be used either in bursts, or simply torrent out in an a gush of agony on its victim.

- Force Maelstrom: First, Darth Sidious would form a Force Bubble around his body, concealing and protecting himself inside. Then, any loose objects/persons around Darth Sidious would swirl around the bubble, through telekinesis. Finally, Darth Sidious would devastate the objects by blasting them away, in a surge of Force Lightning.

- Force Stealth: A power that was used by highly skilled Force-sensitives to mask their Force alignment (Light or Dark), their ability to use the Force, or even their entire presence from other Force-sensitives.

- Force Storm: A volatile dark side Force power capable of creating hyperspace wormholes that were able to displace objects across vast distances and tear apart the surfaces of entire planets. Storms were incredibly difficult to control once unleashed and required mastery in many different Force disciplines.  While he possessed knowledge of the technique before his death, it was only after his rebirth during Dark Empire that Sidious exhibited control of it.

- Ionize: Allows Darth Sidious to overload and damage electronic systems, such as droids.  It's ineffective when targetting organics.

- Shroud of Darkness: Darth Sidious has showcased the ability to Telepathically cloud the clairvoyance and long-range precognitive powers of other Force-Users across the entire galaxy for over three decades, if not longer.

- Telekinesis: Darth Sidious can use this through the Force to put his mind literally over matter, capable of blasting opponents, shielding himself or disarming people, its limits are only those of the creativity that Force User has.

- Telepathy: Can easily manipulate others mentally with the Force to trick, deceive, maim or even kill outright. Can also use this power externally or internally when it comes to illusion creation, manifestation, and manipulation.

- Transfer Essence: A radical dark side Force power used to transfer a person's consciousness into another body, or in some cases an inanimate object.

- Tutaminis: Through the Force, Darth Sidious can draw potentially harmful energy into his body and diffuse it or channel it away completely.

Notable OBD Victories:

Azula (Avatar: The Last Airbender) - Azula Profile
- Bleachverse (Bleach) (can solo the HST)
- Exar Kun (Star Wars) - Exar Kun Profile
- Final Fantasy VII-verse (Final Fantasy)
- Itachi (Naruto) - Itachi Uchiha Profile
- Lord Voldemort (Harry Potter) - Lord Voldemort Profile (can solo the whole verse)
- Orochimaru (Naruto) - Orochimaru Profile
- Space Wolves (Warhammer 40,000)

Notable OBD Losses:

Hal Jordan (DC Comics) - Green Lantern Profile
- Thor (Marvel Comics) - Thor Profile

Other: Darth Sidious Respect Threads.  Not to be confused with Darth Sidious (Disney)

Key: The Phantom Menace | Revenge of the Sith | Return of the Jedi | Dark Empire

Also has apparently mastered nearly every force power and creates new ones for fun

Darth Sidious is a former OBD Champion.