Here's My List:
Classic Era:
Green Hill (Sonic 1 MD)
Bridge Zone (Sonic 1 MS)
Sky High (Sonic 2 MS)
Casino Night (Sonic 2 MD)
Stardust Speedway (Sonic CD)
Marble Garden (Sonic 3)
Flying Battery (Sonic And Knuckles)
Green Grove Zone (Sonic 3D Blast)
Ice Palace Zone (Sonic Robo Blast 1)
Green Flower Zone (Sonic Robo Blast 2)
Jade Coast Zone (SRB2: Mystic Realm)
Frigid Fortress Zone (Sonic Time Twisted)
Boss: Final Weapon (Sonic 3D Blast)
Rival: Fang (Sonic Triple Trouble)
Dreamcast Era:
Emerald Coast (Sonic Adventure)
Neo South Island Zone (Sonic Pocket Adventure)
Radical City (Sonic Adventure 2)
Ocean Palace (Sonic Heroes)
Central City (Shadow The Hedgehog)
Sparkling Seaside (Emerald Ties)
Angel Island Zone (Sonic Advance)
Ice Paradise (Sonic Advance 2)
Sunset Hill (Sonic Advance 3)
Water Palace (Sonic Rush)
Coral Cave (Sonic Rush Adventure)
Boss: Egg Walker (Sonic Adventure)
Rival: Shadow The Hedgehog
Modern Era:
Crisis City (Sonic 06)
Jungle Joyride (Sonic Unleashed)
Tropical Resort (Sonic Colors)
Splash Hill Zone (Sonic 4 Ep 1)
White Park Zone (Sonic 4 Ep 2)
Windy Hill (Sonic Lost World)
Ghost Town (Sonic Forces)
Cyberspace 1-3 (Sonic Frontiers)
White Jungle (Sonic Omens)
Phantasmal Forest Day (Sonic Momentum)
Boss: Giganto (Sonic Frontiers)
Rival: Silver The Hedgehog
Final Boss:
Time Eater
Unlockables:
Angel Island (Sonic 3)
Mirage Saloon (Sonic Mania)
Speed Jungle (Sonic Superstars)
Tails, Knuckles, Amy, Mighty & Ray Unlocked
Updated Version:
Genesis/32X Era:
Green Hill (Sonic 1 MD)
Stardust Speedway (Sonic CD)
Casino Night (Sonic 2 MD)
Marble Garden (Sonic 3)
Flying Battery (Sonic And Knuckles)
Techno Tower (Sonic Clackers)
Marnia Madness (Knuckles Chaotix)
Studiopolis (Sonic Mania)
Golden Capital Zone (Sonic Superstars)
Boss: Death Egg Robot (Sonic 2)
Rival: Knuckles (Sonic And Knuckles)
Game Gear Era:
Bridge Zone (Sonic 1 MS)
Sky High (Sonic 2 MS)
Gigalopolis Zone (Sonic Chaos)
Sunset Park Zone (Sonic Triple Trouble)
Labyrinth of the Factory (Sonic Labyrinth)
Yellow Desert Zone (Sonic Blast)
Boss: Needle Man (Sonic Labyrinth)
Rival: Fang (Sonic Triple Trouble)
Saturn Era:
Dream Weave Zone (Sonic Mars)
Green Grove Zone (Sonic 3D Blast)
Crystal Frost Zone (Sonic X-treme)
Aurora Icefield (Sonic the Fighters)
Radiant Emerald (Sonic R)
Boss: Final Weapon (Sonic 3D Blast)
Rival: Tails Doll (Sonic R)
Classic Fan-Games Era:
Rocky Ride Zone (Sonic Before The Sequel)
Parhelion Peak Zone (Sonic After The Sequel)
Foliage Falls Zone (Sonic Chrono Adventure)
Ice Palace Zone (Sonic Robo Blast 1)
Green Flower Zone (Sonic Robo Blast 2)
Jade Coast Zone (SRB2: Mystic Realm)
Frigid Fortress Zone (Sonic Time Twisted)
Starry Night Zone (Sonic Megamix)
Boss: Silver Sonic (Sonic Before The Sequel)
Rival: Metal Tails (Sonic After The Sequel)
Dreamcast Era:
Emerald Coast (Sonic Adventure)
Riot Train (Sonic Shuffle)
Radical City (Sonic Adventure 2)
Ocean Palace (Sonic Heroes)
Central City (Shadow The Hedgehog)
Crisis City (Sonic 06)
Sparkling Seaside (Emerald Ties)
Splash Canyon (Sonic Riders)
Megalo Station (Zero Gravity)
Forgotten Tomb (Free Riders)
Boss: Egg Walker (Sonic Adventure)
Rival: Shadow The Hedgehog
Pocket Era:
Neo South Island Zone (Sonic Pocket Adventure)
Angel Island Zone (Sonic Advance)
Ice Paradise (Sonic Advance 2)
Sunset Hill (Sonic Advance 3)
Water Palace (Sonic Rush)
Coral Cave (Sonic Rush Adventure)
Boss: Egg Libra (Sonic Rush)
Rival: Blaze The Cat
Modern Era:
Evil Foundry (Sonic & The Secret Rings)
Jungle Joyride (Sonic Unleashed)
Camelot Castle (Sonic & The Black Knight)
Tropical Resort (Sonic Colors)
Windy Hill (Sonic Lost World)
Abandoned Research Facility (Rise of Lyric)
Ghost Town (Sonic Forces)
Starfall Islands (Sonic Frontiers)
Dream Factory (Sonic Dream Team)
Boss: Giganto (Sonic Frontiers)
Rival: Silver The Hedgehog
Dark Era:
Sky Park (Sonic Rivals)
Frontier Canyon (Sonic Rivals 2)
Splash Hill Zone (Sonic 4 Ep 1)
White Park Zone (Sonic 4 Ep 2)
Heiroglyphic Island (Sonic 4 Ep 3)
Boss: Egg Dealer (Sonic Rivals 2)
Rival: Metal Sonic (Sonic 4 Ep 2)
Modern Fan-Games Era:
White Jungle (Sonic Omens)
Phantasmal Forest Day (Sonic Momentum)
Emerald Bay (Sonic Venture Plus)
City Siege (Sonic Forces Overclocked)
Boss: Dragoon E-Zero
Rival: Infinte & Neo Metal Sonic (Sonic Forces Overclocked)
Final Boss:
Time Eater
Unlockables:
Knothole Coast (Sonic Robo Blast! remake)
Luster Lake (Sonic Classic fangame by Hez)
Crystal Cove (Sonic Classic 2 by Hez)
Final Fall (Sonic XG)
Palm Paradiso ("Sonic Forever", what Sonic XG was going to be)
Scrambled Egg (Retro Sonic)
Opal Outback ((Retro) Sonic Nexus)
Sapphire Sights (Sonic and the Fallen Star)
Glacial Galaxy (Sonic Axiom)