[Luxray]

Well i guess i could input my own levels :/

Sonic 1: Marble 2
Sonic 2: Death Egg
Sonic CD:  Collision Chaos 2 (Past)
Sonic 3: Ice Cap 1
Sonic & Knuckles: Doomsday 2
Sonic 3D Blast: Diamond Dust 1
Sonic Adventure: Windy Valley
Sonic Adventure 2: Finalhazard
Shadow The Hedgehog: Egg Breaker (Normal)
Sonic Heroes: Egg Fleet
Sonic 1 GG: Bridge 2 :3
Sonic 2 GG: Underground 2
Sonic 06: Tropical Jungle (Silver)
Sonic Rivals: Meteor Base 2
Sonic Rivals 2: Chaotic Inferno 1
Sonic Advance: Secret Base 2
Sonic Advance 2: True Area 53
Sonic Advance 3: Nonaggression
Sonic Rush: Dead Line 1
Sonic Rush Adventure: Deep Core >_>
Sonic Unleashed (WiiS2): Eggmanland
Sonic Unleashed (Ps360): Dragon Road Night 2

Yeah that's about it :/

[PsyMar]

SADX: Er, the first one for sonic.  Whatever it's called.
SA2B: Chao World.  Excepting that, Cannon's Core, or maybe one of the later Tails/Eggman levels.
SH: Team Dark extra mission in Grand Metropolis.  Least favorite: Any Mystic Mansion not with team rose.
Shadow: Mad Matrix (only because it's the only sonic level I've ever had an untied record on, due to being the first to bother trying to map the place.)
SSR: Didn't play this much, but Lost Prologue had the best graphics.
I haven't really played other games enough to form opinions.

[SonicandInuyasha]

I love all the levels in Sonic 1.

I have lots of favs. it will be too hard for me to list them.

[Telnaior]

Sonic 1: Green Hill Zone 1
Sonic 2: Wing Fortress Zone
Sonic 3: Ice Cap Zone 1
Sonic and Knuckles: Flying Battery Zone 2 (Best in S3K)
Sonic CD: Stardust Speedway 3 (Bad Future)
Knuckles' Chaotix: Level Select Boss (We are allowed to pick bosses, right?)
Sonic Adventure 2: City Escape (Haven't beaten the game yet though)
Sonic Heroes: Final Fortress (Team Dark)
Shadow the Hedgehog: Mad Matrix (or Egg Dealer)
Sonic World Adventure (WiiS2): EGGMANLAND (Day)
Sonic R: Reactive Factory
Sonic Riders: Egg Factory

Also necromancy is a sin >_>

[francisco]

It's kinda weird for me , but ...

Sonic 1 (Genesis) : Marble Zone
Sonic 2 (Genesis) : Hill top Act 1
Sonic 3 : It has to be ice cap, it's that epic!
S&K : Doomsday ^_^
SA : Speed Highway
SA2 : Green Forest
Sonic Heroes : Egg Fleet, just epic.
Sonic06 : Wave Ocean/Crisis City, the best levels in the game, playing with Sonic.
Sonic Unleashed 360/PS3 : Spagonia Act 1 ; Jungle Joyride Act 1
SAdva2 : Sky Canyon 1

And that's it , folks.

[iSonicKid2K]

Sonic 1 - Green Hill Zone Act 1
Sonic 2 - Hill Top 1
Sonic Adventure: DX - Sonic's Windy Valley
Sonic Adventure 2: Battle - Metal Harbor
Sonic Heroes - Mythic Mansion
Shadow The Hedgehog - Westopolis or Glyphic Canyons (Can't decide)
Sonic Riders - Metal City
Sonic 06 - Wave Ocean
Sonic Riders: Zero Gravity - N/A
Sonic Unleashed (360) - Apotos Act 2 (Day)

[Taillow]

Oh hey, another cool thing I missed.

Sonic 1: Labyrinth / Star Light
Sonic 2: Mystic Cave I guess?  I wasn't overly fond of Sonic 2's levels.
Sonic 3: Ice Cap.  Oh, and Hydrocity's gaining a liking too.
Sonic & Knuckles: FLYING BATTERY!  One of my favorite stages ever.
Sonic Adventure: Speed Highway (Sonic and Tails)
Sonic Adventure 2: Pyramid Cave
Sonic Heroes: Hang Castle
Shadow The Hedgehog: Cosmic Fall
Sonic CD: Stardust Speedway / Quartz Quadrant (It's coincidence I swear!)
Knuckles Chaotix (If Shadow counts, this does too): Speed Slider / Marina Madness
Sonic 1 GG: Bridge 2  *Taillow shot
Sonic 2 GG: Gimmick Mountain
Sonic Chaos: They all bore me.
Sonic Triple Trouble: Robotnik Winter I guess.
Sonic Pocket Adventure: They all bore me.
Sonic R: Radiant Emerald (Everybody's Su-per So-nic Racing...)
Sonic Advance: Egg Rocket
Sonic Advance 2: Hot Crater
Sonic Advance 3: Cyber Track / Chaos Angel
Sonic Battle: I... er... pass.  Can't remember any.
Sonic 3D Blast: Diamond Dust
Sonic And The Secret Rings: Night Palace / Evil Factory ((WHO'S GONNA ROCK THE PLACE?)
Sonic Riders:
Sonic Riders: Zero Gravity: Aquatic Capital / Gigas Rocks
Sonic The Fighters: Giant Wing / Death Egg's Eye / Casino Night
Sonic Rush: Altitude Limit
Sonic Rush Adventure: Haunted Ship / Pirates' Island
Sonic Unleashed (Wii): Eggmanland (Day)

[Alexthehedgehog]

the first stage of every single one.

[Rusty Rom]

Here're some of my best wins for all the Sonic Games I play:
S1: Star Light 2
S2: Casino Night 1
SCD: Stardust Speedway 2
S3: Launch Base 1 (Tails) and 2 (Knuckles)
S&K: Lava Reef 1 (Knuckles)
S3DB: Gene Gadget (I don't have any time record here yet, but this is my favorite level for this game)

[andy120195]

Sonic 1:Green Hill 3
Sonic 2:Mystic Cave 2
Sonic CD:Collision Chaos 1
Sonic 3:Hydrocity 2
Sonic & Knuckles:Lava Reef 1
Sonic Heroes:Team Sonic:Mystic Mansion
             Team Sonic Extra:Bingo Highway
             Team Dark:Hang Castle
             Team Dark Extra:Grand Metropolis
             Team Rose+Team Rose Extra:Power Plant
             Team Chaotix+Team Chaotix Extra:Grand Metropolis
Shadow the Hedgehog:Dark:Prison Island
                    Normal:The Doom
                    Hero:Final Haunt
Knuckles Chaotix:Speed Slider 5
Sonic 3D Blast:Diamond Dust 3
That should be it.

[Sxdark]

Sonic Heroes: Egg Emperor / Dark
SR:ZG : Mobius Trip

[soniccoloursunleashed]

sonic 1: green hill
sonic heroes: bingo highway
sa2b: city escape
sonic and the secret rings: night palace
sonic riders: babylon garden
sonic riders zero gravity: aquatic capital
sonic advance: ice mountain
sonic rush: leaf storm
sra: plant kingdom
suwii:spagonia day
su360:apotos day 2
scwii:planet wisp or aquatic park

[Aitamen]

I don't know anything about any favorite "Stage", but I have a number of favorite zones and acts~

but nothing, for me, can ever top EH1.  Home sweet home~

[andy120195]

And I DID forget one:
Sonic R: Radical City(also because of the music :-))

[zackoon49]

S1: spring yard
S2: casino night
S3: hydro city
S&K: mushroom hill
Spinball: toxic caves
3d Blast: green grove
SA: emerald coast (might change this)
SA2: City Escape (duh)
SH: Power Plant
Sonic ohshixt: wave ocean
SU: Dragon Road Day 1
SC: Starlight Carnival
SG: City Escape (Both(duh again))
SAdvance1: neo green hill
SAdvance2: MUSIC PLANT!
SAdvance3: tie between Route 99 and Sunset Hill
SG3DS: Emerald Coast (both)
SONIC LOST WORLD 3DS: Desert Ruins 3 (3rd in the world ATM)
will update later

[DGF]

For me it will probably be(be warned there are two-way favorites in my list):

Sonic 1: Spring Yard Act 2
Sonic 2: Aquatic zone both Acts
Sonic 3 and Knuckles: Launch Base and Sky Sanctuary
Sonic 3D Blast: Puppet Panic Zone
Sonic CD: Quaduartz mines(Good Future jp)
SAdv1: Angel Island zone
SAdv2: Sky Canyon Zone
SAdv3: Twinkle Snow and Chaos Angel
Sonic 2(GG): Green Hill Zone
Sonic Triple Trouble: 2nd stage, I forgot the name XD
Sonic R: Regal Ruins
Sonic Rush: Deadline
Sonic Rush Adventure: Deep Core
SA1: Lost World
SA2: Final Rush/Sky Rail/Green Forest
Sonic Heroes: Hang Castle
Sonic the Hedgehog: Crisis City/Kingdom Valley
Sonic Unleashed (360/PS3): Ababat/Eggmanland
Sonic Colors: Planet Wisp/Asteroid Coaster
Sonic Generations: Sky Sanctuary Act 2
Sonic and Sega Allstars Transformed: Galactic Parade
Sonic Lost World: Desert Ruins Act 2

[SqwareEcks]

Thread got necromanced, so...

S1: Green Hill (it's why I ever started playing these games)
S2: Oil Ocean
S3: Launch Base
S&K: Flying Battery (but the bosses are boring as hell, S&K has way too many "survive until boss defeats itself" fights)
Chaos: Turquoise Hill
TT: Sunset Park
3D Blast: Gene Gadget (I really liked the music, especially the Saturn version)
SADX: Speed Highway (Icecap and Red Mountain are good too)
SA2B: Meteor Herd/Final Chase (Final Rush and Cosmic Wall are good too)
Heroes: Hang Castle (really like Mystic Mansion and Egg Fleet too)
Shadow: GUN Fortress (like Space Gadget and Westopolis too)