VIDEO VERSION HERE: http://www.youtube.com/watch?v=KPAVrl9Ab8U
Original lyrics post: 
EPIC RAP BATTLES OF HISTORY!!!!!!
Turn up the Beat and crank up the Bass,
So I can Mega–bust a Cap–com in this royal brat's face!
I'll call up Rush, Auto, Eddie and Roll
For an assault that'll decimate your Knothole!
I have so many games, it's hard to keep tally,
While your show, Sally, never even got a real finale!
What am I even fighting you for? Where the Hell is Sonic?
He should be my opponent; you're not iconic!
The reasons I'm superior are too many to list;
In the original games, you don't f**king exist! You're the Mary Sue creation of a bunch of stupid DiCs,
And I'd sooner be defeated by Sandy Cheeks!
You're a mistake that should be treated with contempt.
I'd call you a Zero, but that would be a compliment.
I'll forever remain in the gaming hall of fame.
SEGA should have let you die back in "EndGame"!
Was that supposed to upset me, you little Mega–fart?
It's hard to take you seriously when this is your cover art.
You think I'm unaware that I'm not in the games?
Or that I care an iota about that? For shame!
It's hard to be jealous of SEGA's mediocre Sonic,
When you're the queen of the world's most underrated comic.
The way I see it, you're just a violent brute,
Yet you repeatedly fail to end your problems at their root.
You've had, what is it now, your last four titles cancelled?
Wow. Do us both a favor, and go get dismantled.
I'll give you a Knuckles sandwich like I did Fiona Fox,
So hard that you regurgitate your squealing little voice box!
Your creator abandoned you; your career is at an end.
I'll get NICOLE to delete all your NetNavi friends!
My words will stump you worse than those disappearing blocks.
Call me Elec Woman, 'cause you're gonna get shocked, Rock!
I'll take my Metal Blades and cut you down to size.
And… wait a minute, aren't you supposed to be roboticized?
Whatever; it won't matter when I vaporize your head.
Ha! That's funny because the squirrel gets dead!
I'd normally copy your powers, but I'm in no hurry.
After all, I might catch your terminal case of furry!
The fighting robot will shoot you down with extreme prejudice.
And this time, it won't be undone by Genesis.
You sound strained, Blue Bomber. You should go back into stasis.
Your maker shares his name with a twisted, evil rapist!
By the way, I'm not a squirrel, I'm a freaking chipmunk,
Though I'm not like Alvin… Unlike you, you squeaky little Punk!
I've got the brains and the beauty here; all you have is brawn.
And your voice is more cacophonic than "Okkusenman"!
This should go without saying, but I'll spit it for emphasis:
Forget Dr. Wily! Call me your Archie–nemesis!
You're supposed to be a hero, but you're acting like a badnik.
I suggest you go see X, because I think you've gone maverick!
Out of all your petty insults, not one is new to me.
Let me guess: You prefer Sonic with that psycho skank Amy?
I'll get my friends Carmelita, Krystal and Minerva,
Form a posse of vixens and quadruply serve ya'!
When you try stepping up against this righteous Mobian,
You'll find that just like with Air Man, you're never going to win!
(*To the tune of Wily's Stage 1 Theme from Mega Man 2:*) EP–IC RAP–BAT–TLES, OF HISTORY, EP–IC–RAP, BAT–TLES OF HIS–TO–RY, HIS–TO–RY, EEEEEEPIC RAP BATTLLLEESS OF HISSSTTOOORRRRRYYYYYY… DOO–DOO, DOO–DOO–DOO!!!