1. Super Sonic: The golden powerhouse. Transforming through the Chaos Emeralds, Super Sonic boasts unmatched speed, strength, and energy manipulation.
2. Hyper Sonic: Even stronger than Super Sonic, this form unlocks further power through the Super Emeralds. He is essentially on a god-tier level.
3. Knuckles the Echidna: Master of martial arts and chaos energy. He's incredibly strong, possesses immense physical power, and has access to the Master Emerald.
4. Shadow the Hedgehog: A powerful rival with chaos energy manipulation abilities. He's incredibly fast, durable, and boasts chaos control for telekinesis and other abilities.
5. Metal Sonic: A robotic replica of Sonic, Metal Sonic boasts incredible speed and strength, often exceeding even Sonic's base form. He's constantly upgrading and has been seen to adapt to new abilities, making him a formidable opponent.
6. Silver the Hedgehog: Has telekinetic abilities, capable of manipulating objects and even launching powerful attacks. His psychic powers make him a dangerous foe.
7. Dr. Eggman: Though a scientist, Eggman's technological prowess makes him a powerful opponent. He wields powerful machines, robots, and even his own chaos energy abilities.
8. Blaze the Cat: A princess with pyrokinesis, Blaze controls fire and has immense physical power.
9. Infinite: A character with immense power and manipulation of the "phantom ruby," giving him near-limitless destructive force.
10. Mighty the Armadillo: A powerhouse with incredible strength and resilience, often depicted as a capable fighter.
Honorable Mentions:
* Tails: While not known for raw strength, Tails' intelligence, ingenuity, and technical skills make him a valuable asset.
* Amy Rose: Not to be underestimated. She's a strong-willed fighter and possesses surprising strength.
It's important to remember that Sonic characters are constantly evolving and gaining new abilities in different games and storylines. This list is based on common perceptions and may differ depending on the specific canon or game you're considering.