#ss0

Oops, I'm so sorry... I wasn't online for these past days due to irl stuffs. Boy, you're in for a ride.

To answer this, I would assumed you were talking about their anime version and not the manga, so to be honest, I like DM version better, because Toei's anime only focused on the slice of life/ supernatural thing rather than plot progression, so there was no death-T, Shadi's game toned down, Bakura's boardgame was, um, well... Anyway, because the episodelistic (was that the word?) nature of ss0, Yami was more like a wraith that only appeared when Yugi's friends was in danger, rather than a foreshadow that he's an imprisoned spirit. 

I don’t get why people misinformed that “Yami Yugi was only an alter ego before Kazuki Takahashi decided to add Egyptian plot", and it annoyed me. The ancient plotline was already in planning, just probably in a different direction, but the intention of making Yami Yugi a ancient pharaoh was right there from the very start. This is a page from chapter 14, for example:

Here, what Shadi said was “まるで古代エジプトの王「フアラオ」の墓のようだ。。。！！！”, basic translation is “As if this is an ancient Egyptian Pharaoh's tomb”

The English translation cut out a couple of words, but eh, the foreshadow intention is still the same:

While SS0 had a different maze design, and Shadi had a different impression:

I mean Toei had a habit of adding filler and changing scenes (not that Gallop wasn't guilty of the same) but these little changes really made an impact on the storytelling. Compare it to DM version:

I mean, DM had loads of issues but at least they didn't butcher this foreshadow, thank goodness for that.

Like, I'm sure the author wanted you, the reader to connect these little dots and odds together before the big revelation:

“If Yugi and Yami are the same person, why is there two soul rooms?”

“One soul only have one soul room"

“But there are two soul room of two Yugis, because they are two completely different souls”

“If Yami Yugi is Yugi, his room must've been a darker version of Yugi's game room(if different personality counted as a different soul) , or he supposed to lurked in the shadow of Yugi's room (only one soul room per soul, established rule), but instead, it's a tomb/maze hybrid, with ancient designs that is unnatural for a simple modern alter ego”

“So, Yami Yugi came from ancient Egypt, not a dark personality that Yugi created on the spot when solving the puzzle"

Gallop's DM was more guilty of changing stuffs and filler arcs to add more duel in it, but Toei's series was specially guilty in taking stuffs out to add more comedy/slice of life fillers, examples are most of their anime: dragonball, sailormoon, one piece, saint seiya, must have been an 80-90 trend...

So when people said they liked ss0 Yami more and he should be that way in DM, and all of their reasoning was the same old “because he's a psycho murderer that burns people alive”.

And?

AND?

What else do you like about him? So you only liked ss0 for Yami’s memetic murderous status (Not to mention how terribly misinformed that was because there's only two chapter that involved fire out of 53 chapters of the first seven volumes, chemical explosion doesn’t count.)? Did you know Yami was only acting out on Yugi's anger? Did you know he didn't even aware he's a separate person? That's why he didn't react when Yugi got beat up, only when Yugi got angry at what ever villain of the week that he came out, like the Hulk. 

No, he also doesn't “protect" Yugi, he's Yugi's judgement stand-in, punish whomever hurt Yugi's friends, or himself, on Yugi's anger/ behave/ demand. Even in SS0, his attitude is soften over time, but it's not as apparent as the manga, due to them skipping or altering important arcs. 

Death T is an example, Yami's first character development, and the basis for Kaiba’s too, for that matter. When Yami's at the losing end, he was scared, he was lonely, and start distrusting himself, but the voices of encouragement from grandpa and Yugi's friends help him to continue the duel, to have trust, have faith, to believe.

The penalty games were supposed to make the victims reform, “you shouldn't do this anymore" kinda way, but it didn't work well with Kaiba, who had embraced Gozaburo’s teaching to heart. That's why Kaiba's chosen punishment was Mind Crush, to mend his own heart, and remember what he had discarded.

Yami Duelist Kingdom was “I want to save Grandpa, whatever it takes" (willing to sacrifice Kaiba in the process, aka what I coined the “Kiritsugu's ideals", means kill to save)

Yugi was “I want to save Grandpa, but I don't want someone else to die" (Unwillingness to let others die to complete his goal)

Their conflict of interest was suppose to be one of Yami's character development, and help him see beyond his choices, not just do or die. If Death-T and Bakura's game was about trust, then Duelist Kingdom was about trust and choices. Yami always believed he had no other options, so he had to do what he must. Yami didn't know that Mai would show up to repay Yugi’s star chips, so losing to Kaiba will be the end, and his grandpa would stay soulless for good, Yami  also didn't think about asking Yugi for his help against Pegasus, since the loser's soul would be imprisoned in a card, etc. If Yami was to look up, he'd had seen that he has options, not just one choice, but he didn't, that's why he had to learn it.

His fears kept him down, limited on what choice he can have, and in my headcanon, it's probably what made him sacrificed himself and seal himself in the puzzle, because he didn’t get to see any other options. DM anime did toned down a lot of Yami's character development, but well, at least it's better than what we got in SS0.

And so on so forth...

If you only have to compare the two anime, I like DM Yami better, ss0 is just a loose adaption that doesn't truly explore Yami's characterisation, or anyone else, really, for that matter. SS0 is entertaining to watch, if you need some slice of life/ supernatural/ monster of the week type of show, but characterisation wise, it's not good.

“Yeah but in SS0 Yami murdered people left and right, he's so evil I love it"