General Discussion

No, Goku will never do that

He has the power to but would not do it. He did bust a dimension after all. Even SSJ3 Goku at the end of DBZ might be able to do it. Buu could and the non canon Broly could and Broly is weaker than he is and Buu is only slightly stronger.

@Sonata said:

"  No hard evidence, Just powerscalling, ABC logic, and Statements that are never really backed up. Only one who would know for sure is Toriyama.You can debate this till the end of time, no one would be necessarily wrong and no one would be necessarily right. "

Pretty much this. You hit the nail right on the head.

He hasn't, but he likely has the power to. 

No the fathest a dbz character has gone was planet busting really. I mean Goku at max power was able to shake the planet, I think he is a asual planet buster but that's it.

no

@ssjsuperman said:

" no "

why not?

@taichokage: because he has never did so. 
                           because he has never been stated to have the power. 
                           even by powerscaling hes not on that level of power.

@ssjsuperman said:

" @taichokage: because he has never did so.                            because he has never been stated to have the power.                            even by powerscaling hes not on that level of power. "

1. true but is meaningless. There are many characters way more powerful than Goku in comics and anime, but by using only shown feats, Goku would win, so that logic is never accurate.
2. Even back in Z he was nearly as strong as Majin Buu who was a galaxy buster. In GT he could summon the universal spirit bomb. A planetary spirit bomb can destroy a planet easily. A universal spirit bomb... well do the math. He also has destroyed a dimension before in his mere base form. 
3. Well lets see.  A human with a rifile has lvl of 5 in power level. Master Roshi had a levelof 139 and could destroy the moon. A minimum planet buster is at a level of 9000. Frieza who's power level in base form is 530,000 and he could destroy planets with many times the mass of earth with an index finger blast. He also had a form that was about 230x stronger and was capable of full two hand blasts. Cell, who was a few times stronger than Frieza could destroy a solar system. Goku later on literally becoems about 1000x stronger than Frieza. Now I can accept that DBZ SSJ3 Goku may not have been an immediate galaxy buster but he should have been many times solar system buster and over time could certainly have destroyed a galaxy.

@taichokage:
Maybe he could by destroying all the planets in the galaxy or something but no he is not a true one shot galaxy buster. I still think that cell being solar system busting was crap despite hitsuatsu's arguments but that's my opinion, the same way I think sailor moon stomps goku and Dark stomp shenron. I think you make very good case though. Kurohige would do a better job explaining than me lol

1.True enough but there only being planet level feats but saying goku is   galaxy buster just by powerscaing is a little out there.
 
2.non-canon 
 
3.never shown to be a solar system busting  and if he was you would need to be more then   1000x stronger then that to be galaxy level.

@Hirako_Fan said:

"  solar system Buster at best "

multi solar system buster. Cell was a solar system buster and he is many times weaker than end of DBZ 
Goku let alone GT Goku who is above multi solar system busting.