My straightforward top five list of favorite Japanese manga, in order: Akira, Ghost in the Shell, Initial D, Fist of the North Star, then Dragon Ball Z. All of these stories revolve around power struggles, and feature breathtaking battles that expand your imagination. Far Eastern producers are skilled in creating epics of this type, the closest American animated production was the Batman cartoon of the nineties. Dragon Ball Z really drew me into the culture; as a boy, watching expressive men run around screaming about power levels and punching each other in the face was a blessing to this shut in. I ignorantly anticipated episodes after school as if the show weren't already a decade old. By the time high school was over, I had seen every episode through the GT continuation due to my Asian connections.
Dragon Ball Z itself is a continuation of Dragon Ball, which I have chosen to remain oblivious to. To grossly over-generalize, the show stars Goku, an alien fighter of the Saiyen race, from the planet Vegeta [named after its ruling hierarchy] sent to destroy earth. Goku instead loses his memory and becomes earth's savior through a series of fortunate events. Like a genie, Dragon Balls are artifacts used to raise a dragon who grants wishes. Vegeta, the Prince of all Saiyans, arrives on earth to fight Earth's greatest combatants and use the Dragon Balls for himself. All fans of the show usually end up favoring Goku or Vegeta, there are some stubborn viewers who think Gohan is the greatest thing ever; they're obviously deluded and won't be considered in this discussion. For the record, my favorite character is Vegeta. Citing Goku’s desire to defend his family, and not have a heart of malice, Vegeta actually concedes that Goku is the stronger fighter. Goku fans point to this moment to definitively answer whose better; with all of the background out of the way, let’s consider the two prime reasons why they’re all wrong.
First, the sheer amount of assistance Goku receives does not rear its head in Vegeta's favor, until his genius wife Bulma artificially raises his power level to Super Saiyen 4 levels. Goku is trained throughout his upbringing and entered into various tournaments, while Vegeta is presumably off overseeing Napa's destruction of various alien worlds. Goku is trained in *heaven* by fighting *gods*, note the asterisks. Goku was further assisted to defeat Vegeta in the first place. Goku is also given the opportunity to train under extreme gravity conditions during his travels, while Vegeta merely feasts on inferior competition, until they meet again, at which time Goku has ascended to the first Super Saiyen level. This trend goes on, senzu beans; and on, instant transmission; and on, Trunks’ heart medication; and on, fountain of youth Goku... Add in a Saiyen's natural ability to come back stronger from what doesn't kill you, and you have to ask yourself, how much stronger do you return from DEATH.
Which brings us to the final point that makes everything else moot: Goku is dead. Piccolo killed Goku before Vegeta ever arrived on Earth. Either you concede that death is the end of a combatant's participation in this argument, or that dying means nothing, which ultimately means no one is stronger than anyone else. The show would have you believe that the former is true according to certain circumstances, specifically if a villain is killed, then they are not permitted to return, despite the fact that heroes are obviously not bound to remain dead. Even in the after-life, there aren't fighters capable of rivaling Goku at any level until far into the GT series, which means Frieza and Cell should have been locks to constantly return.
I’m not a fan of Lord of the Rings, or any other Fantasy based fiction. My initial attraction to Dragon Ball Z was partly based on the logical concept of power levels and the intricate explanations surrounding their employment. As the series progresses, rationale takes a back seat in favor of a deus ex machina filled theme of heroics. According to the rules of the rules of the Dragon Ball Z Universe, Goku is the strongest being to ever exist, except there aren’t any communicable rules; and if there were, then Vegeta would assume the title and circumvent all future threats by virtue of immortality. At least, that's how I would write it.