You listed it as a game that places "favor" towards the Xbox One and against the OG Xbox.
I'm not going to get into semantics or what not.

They got re-releases, they got remastered or remade.

But by the time that has happened, years have passed since the original release, the story is known (I.E. We aren't going to get a WTF moment in 2020 in Halo: CE once we play the level where the flood gets introduced or when we first step off the landing pod and see the amazing vistas!), the multiplayer population gone and moved on, we know there isn't going to be any substantial DLC or expansions or the like.

Not to mention you need to judge a game based on what else is available at the time... Halo: Combat Evolved was absolutely genre defining and ground breaking on the original xbox at that time, but if you compare it against games of today on the Xbox One, it's actually an average shooter by comparative standards.
And that is the key point... Comparative standards.

The bar has simply shifted. - It doesn't stop being an amazing game, there are just even more amazing games today, even from Microsoft themselves.

I'm not going to play fiddle to this again, but we have already had this discussion and I have already thoroughly refuted it with appropriate empirical evidence.
The campaigns were buggy.
And the online was also a disaster.

The fact that the Master Chief collection has had to be "rebuilt" several times is a testament to how much of a stuff up Halo: The Master Chief collection simply was from start to today. (Where issues still persist, even on the PC builds.)

Impact is certainly an important facet to keep in mind... The Xbox One hasn't really re-defined parts of the industry like the Original Xbox has, it is more of the same.

The SNES was a solid console, so was the N64.
And from a games perspective I find them to both be a wash... The SNES redefined genres, like Mario Kart and StarFox... And the Nintendo 64 with Golden Eye and Mario 64.

And from a hardware point, the SNES pioneered early 3D polygonal graphics and pre-rendered CGI graphics, it was probably the most impactful console in Nintendo's console lineup... Even if on the surface it was an evolutionary update to the 8-bit NES.

Really neither - if anything I prefer the Xbox 360 by a country mile. It's a nice balance of the old era of gaming and the new, and it's library is riduculous. It was a cheaper alternative to the PS3 with pretty much the same solid third party support + Halo and Gears..

But if I had to pick between the two mentioned, I suppose XB One if only for the stronger library, horsepower, and blu ray/aps. Was never too keen on the original Xbox - though at least it wasn't like 80% tethered to the internet and required constant updates just for most of your games to function. 

That's not a bad list for the time. But PS2's had more strong titles in the same and other genres. A PS2 felt like a necessity for avid gamers.

In comparison, I didnt quite feel that with 360 and Xbox One because they have more robust libraries. If we are talking quantity of quality/enjoyable titles, the OG Xbox gets trounced.

And again, I will always consider ports as part of a library. Hence, Halo 1 and 2 are Xbox One games.

Okay, you misunderstood. That's why I said Skyrim is an Xbox One game but not Oblivion.

Again, in my mind comparing consoles should simply mean comparing libraries. Your argument is more about impact on the industry and nostalgia.

I am not denying MCC campaigns had bugs. It just wasn't a broken mess and arguably still a better experience than previous gen versions thanks to better presentation and smoother performance. But again, MCC is a great product now and its still very active.

And again, if you ask me which console was better I look at the libraries. If you asked me which had a bigger impact on gaming in a period where developers were more experimental, I would likely say OG Xbox.

OG by a mile. 360 is top dog, though.

I wouldn't class Skyrim as an Xbox One game anymore than Halo: Combat evolved is an Xbox One game.
They were released years before the Xbox One existed as a device, both games got ported and enhanced on the Xbox One... But the fervor for those titles had waned by the time those re-releases happened... The story known, the world explored, the DLC released.

Comparing libraries is what I am doing.
But you also need to compare the fundamental technical underpinnings.

And you also need to compare the competition. I.E. Halo was leading the industry in game design and hype in the OG Xbox days, not following it like with Halo 5 and the Xbox One.

You need to account for *everything* and not just what an individual thinks is or isn't important in order to forward their own argument.

Again... I have already refuted this prior in another thread with empirical evidence, clearly you aren't going to change your mind on this, so I would rather not waste my time in trying.

The Master Chief Collection still has issues today, even on the PC release.

The Multiplayer population is non-existent in Oceania, you are better off playing Halo 5 instead.

Every facet is important in it's consideration, not just a couple of cherry picked aspects.

As an avid gamer, PS2 never felt like a necessity to me, and I don't think any FPS on PS2 even comes close to Halo 1 and 2.

I guess where we mainly differ then is that to me, Halo 1 and 2 were/are mind-blowing on original Xbox, but on Xbox One, they're just ports of games I already own and played many years ago so hence kinda pointless. Old experiences are never as exciting as fresh new ones of the same caliber.

What ultimately separates the two systems for me is that the OG Xbox has diamond-tier exclusives, and Xbone doesn't.

Gotta also be the reason why we got the Duke right? Just look at those mitts!

I consider any ports part of the library.

I hear ya, but if we're comparing consoles I look at their libraries. Hence, library vs library. The newer console isn't always the superior platform by that standard either. But by that standard, I feel Xbox One is vastly superior thanks to a much more robust library of notable content.

I am not arguing MCC is perfect, but its still easier to recommend than the original releases.

That sucks if you live in Oceania.

I'm not cherry picking, I'm looking at the entire library of both platforms. That makes it easy for me to say Xbox One.

When it comes to FPS and WRPGs, the Xbox was easily better than PS2.

There was a lot of notable and popular stuff on PS2 but not Xbox. Don't wanna go into some sort of list war but it can't be ignored.

Again, I look at the entire library of these platforms and came to my conclusion.