Are you crazy?
Before itachi could even activate his crappy Sharingan, goku would have ***** slapped him all over the place
(killing him with the first hit)
Even if goku got caught in his friggin mangekyou sharingan, I don't even think it would hurt him that much :S
No anime can win against DBZ, its just impossible.
Lets compare Goku vs Itachi.
Goku would easily own the **** out of him.
Why?
1) Mangekyou sharingan wouldn't hurt him (I'm reffering to the crap Itachi did to Kakashi, so if he can do anything else with it in the manga, please don't spoil me, I'm pretty sure that wouldn't do any damage either though....)
And even if it could hurt him, he can stand so far away that Itachi can't even see him...and then just beam his butt.
2) He could simply blow up the planet and be done with it.
3) He could *blink* and Itachi would just explode (like Frieza did with a mountain >_>)
5) Even with Sharingan Itachi couldn't possibly predict his moves, and even if he could...his body would be to slow to react so he would simply get pwned in the face.
Power, Goku wins
Speed, Goku wins
Jutsu's (Kamehameha, Kiezan, Ryu Ken, Genki-dama, Kaioken, SSJ 1 till 3, and Solar flare...but I forgot the jpns name for it) Goku wins
Experiance, Goku wins
Taijutsu, Goku wiiiiiiiiiiiiins
But all of the above wouldn't even be necessary..the fight would probably go like this:
Itachi: "Mangekyou sharingan"
*Goku powers up*
*Itachi dies do to the masive shock wave.*
Hell even Nappa would own Itachi + Legendary Sannin.