COIE clearly had a much bigger impact, on every level. IG, for the most part, is a story that catored to the "cosmic" nerds who like power tripping, and hit a big "reset" button by events end, and mostly only mattered to Thanos and his close circle of supporting characters going forward.
That said, I think I'd rather read IG today then COIE, and think it told a much better story overall.
I personally think that Infinity Gauntlet (And the Infinity War and Infinity Crusade that follow after) is a better composed story arc than Crisis on Infinite Earths. Both are massively creative and have had major impact in the comic book world and in their respective fictional universes, but the Infinity Gauntlet truly portrayed a hungry villain's rise to ultimate power and the consequences that follow when a mortal achieves godhood.
What I loved the most about the conclusion of IG is that despite becoming the God of an Entire Universe, Thanos never became enlightened or better for it. Perhaps the experience proved to him how addicting power can be, but as with Adam Warlock, Cosmic Supremacy did not make either of them better people - they were still the same flawed broken characters they've always been, just with the power of a supreme being. As a concept I felt it was stronger than Crisis.
COIE has more influence and was in a bigger scale, also made the biggest impact as far as any cross over events concerned. basically decided the direction of DC comics in the next 30 years. that's why everything in dc has been viewed as pre-crisis or post-crisis, hell even in battleboards
however with marvel popularity rising Infinity Gauntlet has grew into a more well known story
I liked Infinity Gauntlet more. Although, COIE definitely had a bigger impact. With that said, I somewhat dislike COIE. I have never liked comics that try to put multiple version of the same character in one story for the sake of creating a "bigger scope"
IG is one of the best storylines of all time. It's inspired one of the most anticipated films of all time as well. Coie is very forgettable. It's about preference in the end but to me IG is on another level.
Both hold up fairly well imo. Trying to laugh down opposing opinions over what is an entirely subjective opinion shows nothing except immaturity.
The upcoming movies will threaten to place IG as a cultural #1. But COIEs was legitimately company-changing at the time. It refreshed and streamlined DC and was arguably the only necessary reboot in major-company comic history. For my money, it felt more epic. And both also serve as reminders of how much more issue space they used to give big events compared to more modern ones. I miss the longer-form events as a storytelling format, relative to the usual 6-8 issues (and shorter, less packed issues) they're given today, as well as the endless tie-ins that aren't quite required but also lose something if you're not reading them. These self-contained, lengthy, epic stories were excellent, and a big reason I got into comics originally.
Crisis on Infinite Earths is far more crucial to DC then Infinity Gauntlet was to Marvel, because the events of IG were reversed. So in terms of impact, COIE is the more consequential event.
The Infinity Gauntlet, in my opinion, is just a better story. Yes, it has its flaws and it has some PIS - why the Living Tribunal refused to subdue Thanos, but had no problem forcing Adam Warlock to relinquish the gauntlet was complete stupidity and a story telling cop out - yes. But IG is still a greater story because of its concept.
Yes, Crisis was EPIC. There is no doubt. I love Crisis on Infinite Earths. Don't get me wrong. But the concept wasn't as strong to me as Infinity Gauntlet. COIE was very simply - the Anti-Monitor is using his power to destroy realities at a time. Our heroes must stop this cosmic tragedy. It's a classic good vs evil, defying the greatest odds cosmic battle. Great. Plenty of those.
With the Infinity Gauntlet it's not like that - you have Thanos, a pyschologically tormented being who finally achieves cosmic supremacy only to realize it's just not enough. Becoming "GOD" achieved nothing. Thanos could not win over Mistress Death. Despite all of his achieved power, she not only refused to love him, she actually ended up hating him. To make matters worse, she literally saved the devil from Thanos and joined Galactus and the cosmic alliance, betraying Thanos, in an attempt to stop him.
Thanos thought that ultimate power would make him worthy of Mistress Death's love. It didn't. He thought it would make him happy. He was just as miserable with such power, if not more so. Adam Warlock then obtained the gauntlet. He obtained no more peace or happiness than Thanos did. Power or Godhood did not "fix" these characters. They were still **** ups.
IG is just a more intelligent and meaningful story than COIE is. Both great work. But IG takes this one for me.