After his fight with Vegeta, Goku is hospitalized in Wukong Hospital. Wukong is the Chinese name for Goku, as well as being the name of Sun Wukong, the character from Journey to the West (a piece of Chinese folklore) that Goku is based on.
Cell is the only main villain that Goku never bites during battle.
Vegeta almost always addresses Goku by his Saiyan birth name, "Kakarot", but has on rare occasions addressed him as "Goku". Vegeta says the name "Goku" only eight times. This is a mistake by the English dub team. In the Japanese version he ONLY calls him Kakarotto
Like in the previous series, Dragon Ball, Dragon Ball Z has many naming conventions/jokes. Saiyans are all named after vegetables. Vegeta, both the prince, his father and the Saiyan home planet (originally named Planet Plant) is the first half of "vegetable". Raditz is 'radish', and his brother, Kakarot, is 'carrot'. The villain Frieza comes obvious, as well as his brother Cooler and their father King Cold. The Briefs family are all named after type of underwear, Bulma comes from 'Buruma', the Japanese transliteration of bloomers, Doctor Briefs, Trunks, and Bra are all self-explanatory. And of course, various characters named after foods. There is the shape-shifting pig, Oolong, as in the tea. There are many that are self-explanatory like Ginger, Spice, Blueberry, Raspberry, Raisin, Almond and Apple. The name Videl is actually an anagram of "Devil" because her dad is Mr. Satan.
Freeza and Goku's fight in Namek is the longest battle in anime history, with a duration of a little over four hours