Misprinted Magic the Gathering cards are weird. Even weirder yet, are the folks who collect and/or sell them. Whether you're a collector or a seller, you should have a base understanding of what's desirable and what isn't. The tricky part is that as new cards are printed, the trends and population of misprints change. To the individual who opens a misprint, but is not familiar with the market, to them their card is usually a god given gift from the heavens, even if it's 1 pixel off from the normal version of the card. I'm tired (and so are all of the other collectors) of seeing your garbage. Here is a list of misprints that I just don't care about any more, and neither should you.
Ok, this one is a matter of severity because the core concept behind the misprint is actually cool. What's happening is that for one reason or another, the layer of black ink being printed on the pass for the art and mana cost is faded or missing. The problem is that this error has become insanely common with recent sets, and the variations of the severity. Unless you have the most extreme possible case, don't bother showing anyone.
One Side Normal, the other Slightly Offset
Another severity based issue. While this misprint is visually similar to offset/miscut cards, it has historically gotten special treatment due to the difference in the technical process that ends up generating these misprints. Well, guess what, it's time to apply the miscut rule to these misprints now. If the "miscut side" doesn't show a 2nd card, or the edge of a sheet, don't bother wasting anyone's time posting your cards.
Missing stamps (includes partially missing stamps)
For this one I'm talking about the holostamps used to 'authenticate' rare and mythic rare cards. Since they've been implemented, there's actually quite a few variations of possible holo stamp errors (I'll update my beginners guide with the complete list soon). When the stamp is missing or partially missing, it just isn't exciting anymore. First, it's a really common error (this might be a theme of the article that you've caught onto). Second, it's visually boring.
Slightly Smudged or Blurred/Bold Text
Following the theme of the article, slightly smudged text is common and visual appeal is entirely severity dependent. The overwhelming majority of these misprints are garbage, and not worthwhile. This is especially true with the recent release of Modern Master 2017, where this error is out en mass.
Slightly Offset Holo Stamps
Another severity based misprint! The stamp needs to really be somewhere it's not supposed to be for anyone to give a f about these. Let's say that the new rule of thumb is that if you can't place a stamp in between the position where the stamp is, and where it should have been, that it does not qualify as an error that anyone should care about. I'm a snob, but...your misprints are garbage.
"But Jason," you say, "I sold a slightly (insert whatever lame misprint here) for like a gorillion dollars! What do you mean nobody cares about these misprints?" Ok, I get it, sometimes there are exceptions to the rules, but that doesn't mean that your misprints aren't still garbage. Sometimes a garbage misprint on a highly desirable card still sells because obtaining decent misprints on those cards is extremely costly. Also, you get folks who aren't always aware of what they're buying, who end up buying garbage thinking it's neat. Yes I'm a snob, but your misprints are garabage <3.