Yu-Gi-Oh was originally a manga that ran from 1996 to 2004 that was written by Kazuki Takahashi and published by Shonen Jump, the same company that released other manga like Dragon Ball, Death Note and One Piece. It is best known for its trading card game that has become popular worldwide as well as the second anime that came out in the early 2000s (then later abridged by Little Kuriboh).
It is also a property that I believe has the potential to be adapted into a good live-action film if done right. Some of you now are probably thinking, "Is he serious?" or, "Oh great, another shameless grab for money" but hear me out. There is much more to Yu-Gi-Oh then you may believe.
Spoilers for Yu-Gi-Oh bellow.
A little background
Many people seem to be under the assumption that the Yu-Gi-Oh manga and the second anime were made after the card games as basically to be extended commercials, similar to western shows in the 80s like Transformers, He-Man and Thundercats. In reality however, Yu-Gi-Oh is more like Teenage Mutant Ninja Turtles. An interesting and darker work that was dumbed down to sell toys.
For the first 59 issues, the story was about Yugi Mutou, a short, bullied kid with a love for games. One day he is able to complete the Millennium Puzzle, a cursed ancient Egyptian artifact he has spent the last eight years trying to figure out. With its completion, he gains its dark powers and is able to turn into Dark Yugi, who uses his Yami no games to fight evil and the corrupt, possibly even killing them if he has to. These include serial killers, thieves, corrupt business men, dangerously obsessive collectors (as in they are willing to kill), Abusive Teachers and even a stand in for Leatherface.
The card game element only appeared in a few issues and was really only associated with Seto Kaiba, who is depicted as a rich prick who lets his obsession with the game to go too far, leading him to rob and assault. What's great was that it never goes into moral panic or crazy ideas that the card game was evil or was somehow causing people to do bad things like it could have easily devolved into.
I highly recommend you check out the first 59 issues as they are really enjoyable and go into far deeper topics and character development then you would expect. Or at least I would recommend the original anime (called season 0 outside of japan) that is slightly more tamed adaptation of the first three arcs but is also enjoyable (though weirdly, most online versions seem to crop it which really does hurt it).
So what happened? Basically pressure from Bandai and later Konami forced Kazuki Takahashi into turning the card game into the main focus of the manga and starting with issue 60 (the beginning of the Duelist Kingdom arc), the manga slowly became a commercial. The second anime series ignores the first three arcs, only summing up the important information in the first episode and became even more of an obvious commercial.
How Could A Movie Work?
A movie could very easily turn into a 90 minute advertisement if done poorly (like the first three anime films). But if done correctly, it can be a movie that both embraces its darker and deeper early years and its commercialization to become something rather special.
The biggest problem of course is how you deal with the card game element as you can't (and Konami wouldn't ever allow you) to get rid of it. In my opinion, the way the card game should be shown in a live action adaptation is basically to show it as it is, a card game people play as a hobby, love collecting and go to conventions & tournaments for. Basically, be an analogy for fandom that both praises the positives and shows the negatives.
As with the characters, you wouldn't have to change them much to make it work as they are all rather interesting and great starting points. Yugi and Kaiba (who with Bakura is the best candidate for the antagonist) I already mentioned in the background so we will go over them again.
Jonouchi (named Joey in the 4kids dub of the second anime) is Yugi's newly made friend who comes from a rough family, has rage problems and has issues with his sexual identity (the manga seems to hint in the early issues that he may be either gay or bisexual before dropping it). Anzu (Tѐa) is a highly intelligent woman who wants to move to America and unlike what the 2nd anime may show, she isn't a useless side character. Honda (Tristen) is a very vain man with delusions of grandeur (basically a Japanese Rimmer) and Miho (a character who appeared in one issue of the manga and became a main character on the first anime) is a shy librarian.
Then finally there is Bakura, a poor soul who isolates himself from the rest of the world as everyone he ever knew and loved either dies or goes into comas. All accept one, Dark Bakura. The dark presence that lives in his Millennium Ring who comforts him while secretly the one causing his pain.
Then finally there is the tone and plot, do you go with the darker beginnings or the lighter tone of the later years. Personally, I would take a tone that the original anime took which was somewhere in between (in the 12/PG-13 area if we were to put a rating on it).
The storyline would be an adaptation of both the School arc and either death-T or the Dungeon World arcs depending on the villain. Ultimately, Dark Yugi is Yugi's wish fulfillment, a strong, courageous and confident man who is willing to stand up against evil doers. He learns through the story to be a stronger person who is willing to stand up against both Dark Yugi and Kaiba/Dark Bakura by himself.
But ultimately, this is just my view and ideas. Please feel free to disagree or discuss your own ideas and thoughts in the comments.