Dragon Ball Watch Order
The short answer is Dragon Ball, then Kai, then Super, then Super Hero. The long answer is about which forty percent of Z you are allowed to skip.
Watch Dragon Ball, then Dragon Ball Z Kai, then Dragon Ball Super, then the film Super Hero. That covers the canon and skips nothing that matters. Everything below is the reasoning, and the two places where the reasoning gets genuinely contested.
Kai instead of Z, and it is not close
Dragon Ball Z and Dragon Ball Z Kai tell the same story. Kai tells it in roughly half the running time by removing filler, recap and the padding that made the original notorious. The Namek arc alone is famously stretched across dozens of episodes covering minutes of in-story time.
The case for original Z is nostalgia and the original score, both of which are real and neither of which helps a first-time viewer. If you are starting now, start with Kai. If you grew up with Z, watch Z, and you already knew that.
Do not skip the original Dragon Ball
The most common shortcut advice is to begin at Z, because Z is where the series became what people mean by Dragon Ball. It is bad advice for one specific reason: the original is a comedy, and Z is not.
Starting at Z gives you a protagonist who is already an adult, already the strongest man alive, and already surrounded by people whose relationships were built over a hundred episodes you did not watch. More to the point, it hands you a tonal register with no idea it was ever different. The joke of Z is partly that a gag manga about a feral child hunting wish-granting orbs turned into an interplanetary war story, and you cannot get that joke from inside the war story.
The films worth watching
Most Dragon Ball films are non-canon side stories, entertaining and disposable. Four sit inside the story: Battle of Gods, Resurrection F, Broly and Super Hero.
The first two are the awkward ones. Both were adapted into the opening arcs of Super, which means watching the films and then the series gives you the same plot twice, at different pacing and with different animation quality. Pick one. The films are better made; the series arcs are better integrated. There is no correct answer and anyone who tells you otherwise is describing a preference.
GT is optional and the reason is not snobbery
Dragon Ball GT was produced by Toei without Akira Toriyama writing it, continuing past the end of the manga. Dragon Ball Super was later made as the official continuation, which places GT outside the story rather than after it.
That is a statement about continuity, not quality. Watch it if you are curious, after Super, and treat it as what it is: a spin-off made when the source material had run out. It will contradict things.
Where Daima goes, honestly
This is the one place a watch-order guide should admit uncertainty, and most do not. Sources disagree. Some place Daima chronologically between the end of Z's Buu arc and the start of Super. Others place it after Super and after the Super Hero film, sitting before Z's final epilogue.
The practical answer is to watch it last, after Super Hero, regardless of where it sits on the timeline. It was made most recently, it assumes you know everyone, and nothing earlier depends on it. Watch-order guides that state its placement with total confidence are picking a side in a disagreement they are not telling you exists.
The version that is actually the problem
Not the order. The dub-versus-sub question does more damage to a first watch than any sequencing decision, because the two versions of this franchise are tonally different works. The English dub gave Goku a gravelly adult voice and a heroic register; the Japanese casts him with a woman playing him as a cheerful simpleton who happens to be the strongest being alive, which is much closer to what the writing is doing.
Neither is wrong. But a viewer who watches the dub and then reads that Goku is selfish and childlike will be confused, and the confusion is a translation artefact rather than a disagreement about the character.