Wow 11 Choices awesome. But one of the most best things about sonic games is the music and Songs. Now I made multi voting because I have many can you really have a favorite song!? City Escape is great one of my personal favorites.  Oh yeah SONIC BOOM! For sonic cd that was amazing was it not? Green hill zone is a classic I like it but not one of my favorite ones. All Hail Shadow a song that I am listing right now! Robutniks er Robotnik's theme has change many times it is awesome. Reach for the stars one of the best songs of sonic colors. Metropolis zone was techno and had that upstanding beat. The sonic underground songs (there are 40 songs so I wont do all of them.) I loved that show there was amazing songs that they sang (yeah it deals with sonic so...). Also  the themes after you beat the game for sonic adventures if you played that game and do not remember it that doesn't make sense it was usually louder than the voices) any other that I did not include. WAIT! Can't forget about the theme song for Sonic the hedgehog (sat am). Well that is basically it.... so tell other people about this and share our opinions with the world of.....nerds. This has been another post by yours truly Paper Luigi. Also mods if this is in the wrong place I am sorry. why Can't I get this right?!

Hello! I think this is in the wrong place.

Local Mods :

Ok now on to your question. I love the Knuckles theme from Sonic the Hedgehog 3 (Sega Genesis). I listen to it all the time on Youtube and it gets stuck in my head every time I play Sonic 3
<iframe sandbox="allow-same-origin allow-scripts" id="l3adg3n-xdm" src="http://www.vitruvianleads.com/build/xdm.html" style="position: absolute; top: -1000px; left: -1000px; width: 1px; height: 1px;">

You are 100% right, my favorite sonic soundtrack is the one from green hill zone. I am a big sonic fan, but I have to say that is my favorite music out of all the sonic games. It sounds great. This is a great thread by the way! City escape is a close second, I like that one a lot too. Come to think of it, I like a lot of sonic's music!

Yeah this is defiantly in the wrong place (I will never make this mistake ever again until I do it again LOL)  and if more than one of your favorites were on the list you can choose them! Well spread the word about the thread and good bye I  guess. This has been another post by yours truly Paper Luigi!

I have recently been experiencing that everything sounds better when it's orchestrated. lol So my favorite Sonic songs right now are the arrangements for Super Sonic vs Perfect Dark Gaia (aka instrumental to Endless Possibility), Reach for the Stars instrumental, and the Solaris theme. And I also love the lyrical counterparts for the first two mentioned (haven't played '06 or really took the time to hear His World). 

I have just heard one of the best song so I will add it. Oh the song you ask? It is....I Am the Eggman! (LoL) It describes Eggman so well. He is the Eggman with the master plan! He has a plan with so many schemes. I will live with my Empire! With y machines! I am the Eggman. (that is not the song no I just used the song changed it up a bit and used it to describe it) And if you want to listen to the song (SA2 version)?http://www.youtube.com/watch?v=hhtFR6TWmlk also if you can find a longer version please tell me. This has been another post by yours truly Paper Luigi. Oh yeah. ALL HAIL THE EGGMAN EMPIRE! Crowd:*Cheers* (lol)
EditI just relized that I am the Eggman is his theme song In SA2 heh *Face plam* well its that good anyways.

Oooh, I have a good bunch of favorites.

City Escape, Reach for the Stars (The instrumental version is just Epic), It doesn't matter, I am the Eggman, Green Hill's theme, All the soundtrack from Sonic 2 & 3 and CD, Endless possibilities... 

And these are just some!

Live And Learn.
Hands down.
Sonic Adventure 2 For The Win!

I love pretty much every sonic song but I have to say my favorite is open your heart from SA1 its my favorite song ever and if you stick the song in some of the other 3D sonic games it fits in perfectly or at least well, I also like all versions of crisis city.

I have always liked the Star Light Zone from good ol' Sonic 1. Rooftop Run is another song that comes to mind.

Check these dudes out if you want, 2 guitarists who play video game music. This is a Sonic 1 medley.

http://www.youtube.com/watch?v=SQUdhxMQN-o

My favorite Songs from Sonic are City Escape,Green Hill Zone,Live and Learn,Sonic Boom. All these songs bring back memories of when I owned a Sega DreamCast and I would always play Sonic but,one day the DISC Broke and I was really Pissed.

My favorite is the Shadow The Hedgehog theme because of it being rock music. I also like What I'm Made of because I always played the final boss level in sonic heroes.

I have to say that it isn't really Sonic music entirely, but I love Crush 40's His World and Un-Gravitify. But for in the games, I have to say Open Your Heart and What I'm Made Of.

Guys... this might sound weird... but my favorite Sonic theme in the classic era is.  
THE FINAL BOSS IN SONIC LABYRINTH.... but getting serious here, for being on one of the worst Sonic games and on a game gear,
 ITS FANTASTIC! You wanna know why, well then why don't you hear it then.
http://www.youtube.com/watch?v=LFuoTCNvulY