First off, if you are going to be rude and come here just to comment, "oh no, not another dbz thread" or something similar, please be mature and just leave this thread now, Thank you.
Secondly, I'm using cannon and non-cannon(anime). And if you have a problem with that, again , please do not be rude by commenting something immature.
OK now to the main point.
Goku's battle/power/strength levels in the beginning of buu series:
Ss1: 3,000 kilis
Ss2: 6,000 kilis
Ss3: 24,000 kilis
It was stated that it takes 200-300 kilis to destroy a planet. Since they never specified how large of a planet I'm going to assume (since they were on earth when it was stated) that they meant an average size planet around Earths size.
Goku's Ss1 can destroy: 10-15 planets
Goku's Ss2 can destroy: 20-30 planets
Goku's Ss3 can destroy: 80-120 planets
No one in DBZ can technically be a "solar system" buster. (Unless someone can actually find out how strong Vegito and Buuhan were, which I find impossible).
Our Sun is 333,000 times the mass of earth and 1,000,000 Earths can "fit" inside our sun.
DBZ character can however, destroy most of the planets within a solar system depending on how big they are. Which in a way, is destroying a solar sytem (just leaving the sun). But they would not do this In one big blast. They would have to visit each planet then blast it away....Goku would have enough energy as a Ss3 to visit 80-120 average size planets and destroy them without having to "re-charge".
If you have any input please let me know! And I ask again, please do not be immature fellow viners......
Here are a couple links to back up the earth/sun comparison.