Digimon & Inuyasha

At risk of showing my age, The Twelve Kingdoms blows most modern isekai out of the water, even with its flaws. The MC‘s journey and character growth is amazing, and the world building is incredibly unique.

Re:ZERO or Ascendance of a Bookworm (underrated in my opinion).

Konosuba

So many isekais have great starts, but fall off execution in the second season. Maybe they run out of ideas, or just had a good concept, but then lacked creativity to keep the plot interesting... So there are a lot of S1's

Sword Art Online Season 1

Log Horizon Season 1

Level 99 Villainess

Shangri-La Frontier

Rising Of The Shield Hero Season 1

Overlord

Mushoku Tensei: Jobless Reincarnation

I really liked Uncle from another world too, but I wouldn't list it to that question. I guess because it's more of a comedy than with a spanning story and depth or development.

Scrolling through the comments to remember some of them,

• Mushoku Tensei - great - the first two seasons have exceptional world building, story telling, contrasting, and developments; not everything is great, but a lot is; for me, last two seasons fell off a bit
• Grimgar - very good - very unique, great world and characters and relationship between them
• Ascendance of a Bookworm - very good
• The Eminence in Shadow - very good - exceptional satire
• The Magical Revolution of the Reincarnated Princess and the Genius Young Lady - very good until the ending, with exceptional visuals and vibrancy
• Life with an Ordinary Guy Who Reincarnated into a Total Fantasy Knockout - very good - great comedy with a gender bend/swap

/edit: Found two more from my list of good/decent non-harem isekais I replied to some no longer existing lemmy post.

Space Jam.

Honest answer, much like typical shonen series I find isekai really boring and hard to watch. If I see "reincarnated" or "another world" in a show's title it's pretty much an instant pass from me.

Give me more DanDaDan dubs pls.

Reincarnated as a vending machine, I now wander the dungeon is my latest favorite. It's funny and a cute show.

My favorite isekai is Farscape.

But if it has to be anime: Inuyasha.

Konosuba Since it's a parody.

I don't like isekai.

Overall, probably Slime Isekai. It's got a good mix of wholesomeness, action, comedy, and world building. And it has just the right amount of OP in the MC.

Overlord is a good runner up. Great character development, good story and humor, intriguing world, etc.

Mushoku is easy top 5 but the bullying and horny drop it down a few notches for me.

Konosuba is also top 5. It nails the parody.

For non-anime, Reincarnated as a Sword is my favorite isekai light novel series, not that I've read all that many isekai light novels. However the anime adaptation was mediocre at best. It barely touches on the deep world creation and character development found in the LN.

For video game isekai, Shangri-La Frontier. No trapped in a video game nonsense. No completely unrealistic game mechanics. The game feels like it could be a real game. And the MC is OP only in the sense that they're good at games, not because of cheats.

Villainess isekai is practically it's own thing now and I have my favorites there as well but the classic is All Routes Lead to Doom.

I really love isekai so I could keep going but I'll stop here before I start talking about Trapped in a Dating Sim.

Konosuba

Being a parody, it subverts most tropes of isekai anime. Its humor is exactly my type too.

Honorable mentions:

• Cautious Hero
• Saga of Tanya the Evil

Most other isekai anime have the same cookie-cutter plot, making them so predictable and boring. Or they have an interesting premise, but waste it with poor writing and dumb characters.

uhh... spirited away?

mushoku is up there if we are talking about the modern kind of isekai

I'll let you guess from my instance 😁

tensei shittara slime datta ken

I like Overlord. Its got good worldbuilding but it also doesn't always take itself too seriously and throws in some comedy every now and then to keep it lively.

I also really liked Knight's & Magic. There are not enough medieval fantasy / mecha hybrid shows out there, despite anime being the perfect medium for it.

Skeleton in Another World was a fun one once you get past the first episode. The attempted rape scene right in the beginning just shows too much on screen IMO, it would have been better to cut some of it short and show the scenery around more rather than what was actually shown. Very uncomfortable, which I hope is what its supposed to make the viewer feel, but then literally none of the rest of the show is every that intensity. Like it was almost Perfect Blue levels of showing too much for too long.

.hack//SIGN

without it we wouldn't have many of the isekai animes as we currently do

Mushoku is probably the best by such a large margin i couldn't think anyone answering different was serious. Log horizon is probably the only isekai that's done the modern game junk well.

Visions of Escaflowne was pretty great. It had basically everything, a fantasy world, giant mecha and a Yoko Kanno soundtrack.

Re:Zero, Konosuba, Overworld, and That Time I Got Reincarnated as a Slime are some of the best, alongside SAO which started the modern version of the genre.

I liked Grimgar a lot.