I see a lot of people give goku props for his fighting abilities and his hero image , but let's have an honest look at the record of earth's greatest "hero", shall we?
First body he caught was his own surrogate grandfather, a kind old man who opened up his own house and treated him like his very own son and how did he return this act of saint-like generosity, he crushed him under his foot
Dbz rolls around, the first body he caught was his OWN brother. Granted he deserved it, but Goku obviously has no qualms about killing family as we will soon find out later in the series.

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Enter the saiyan saga, Goku"absent mindedly" forgets that he needs to be wished back and on earth where the resulting battle is taking place. Nearly all his friends save Krillin died in the following battle.While his friends are picked off one by one, krillin bemoans the fact that goku isn't there to stop the deaths of his friends. Stupidity kills indeed.
Now on Namek. Goku shows otherworldly feats of speed and perception from his 100x gravity training, he makes quick work of the ginyu force. It would have been so easy for him to stop Vegeta whose attacks resulted in the deaths of 1)Recoome and 2) Burta. Somehow, Vegeta manages to execute both of them in front of goku, who at this point wasn't very much faster or stronger than the Ginyu force members himself. Another Goku moment

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Spares frieza, who would have most likely gone on to terrorize the universe if it weren't for Trunks, leading to the deaths of untold numbers throughout the galaxy's spectrum. Yes, spare the guy who destroyed your home planet without hesitation who operates a planet exterminating mega-business.
Cell Saga, Semi-perfect cell is about to explode due to your personal negligence by entrusting the fate of the world to your teenage son. What do you do? You instant transmission him to your sensei's house/planet. A nice old guy who fed you, took you in and put new clothes on your back and taught you martial arts techniques . Sounds familiar?

By the way, how many plants, animals and people died using up their energy for the spirit bomb attack. Now think about the universal spirit bomb.
Buu saga, goku fights majin buu, the new greatest terror facing the world at large, instead of finishing him when he had the chance like well any hero would do, Goku decides to keep him alive for "fun" but his time limit runs up, sending him back to other world. The result of letting buu live, every single person on earth save Mr. Satan dies, When the earth is wished back. Goku then chooses mr. satan over his own family and his closest interspecies friend who were absorbed or killed or something.