Kanji: 孫 悟空
Hiragana: そん ごくう
Hepburn: Son Gokū
Shuiesha: Usually Son Gokou (sometimes Son Gokuh, Son Gokuu, and Son Goku)
Toei: Usually Son Gokou (sometimes Son Gokou, Son Gokuu, and Son Goku)
Bandai: Usually Son Gokou (sometimes Son Gokuh, Son Gokuu, and Son Goku)
Funimation: Goku (sometimes...