I'll second (well, third) KonoSuba for fun comedy/meta isekai.

Let's start off with some of the big ones: Rising of the Shield Hero, Gate, That Time I Got Reincarnated as a Slime. All good in their own rights.

I'll follow up by throwing out some of the less traditional or serious ones: Reincarnated as a Sword, and Reborn as a Vending Machine, and So I'm a Spider, So What? each do things nontraditionally, as the names indicate, which is fun. The spider one is probably the most serious and interesting, but the others are fun too. They're each distinct, I just grouped them because they're an interesting take on reincarnation.

Problem Children Are Coming From Another World, Aren't They? is fun, has hilarious OP characters, and Black Rabbit is a cutie.

Cautious Hero: The Hero Is Overpowered but Overly Cautious. Oh man, this one is both hilarious and interesting. As the name implies, well, the hero is both ridiculous OP, but also absurdly paranoid, but it does develop beyond that, thankfully. Also, great OP.

Dead Mount Death Play builds a very intriguing and unique world, and I give it props for that. It starts out a bit slow, but as the season goes on, and more is revealed, it really sucks you in. Major points to this one because I don't immediately know or at least suspect every plot point. I probably wouldn't say this is the best out there, but I might say it's the most interesting on my list, and I certainly recommend it. Bonus points for shark girl.

Skeleton Knight in Another World is another one with comedy elements. Really funny MC, and it's kind of reverse-Overlord. He's a skeleton, but he's usually just the most wholesome dude.

Isekai combined with slice of life: I've Been Killing Slimes for 300 Years and Maxed Out My Level, and The Devil is a Part-Timer! The first one is pretty wholesome, as I recall, and the second is...alright. It's got some great elements, but might not be the best overall.

Isekai with the longest name: The Misfit of Demon King Academy: History’s Strongest Demon King Reincarnates and Goes to School with His Descendants. Not everyone's cup of tea. Comedic, with one of the most OP heroes in any anime ever, probably. You may have seen the "Did you really think X would be enough to make me Y?" memes, the most famous probably being "Did you really think killing me would be enough to make me die?" But do to how insanely OP he is, it could be boring for some if you don't enjoy the - often somewhat dry - humor.

Log Horizon is another video game isekai, similar to Sword Art Online.

Ya Boy Kongming! isn't primarily an isekai, but has elements and is fun, so I'll include it anyway. Also, another kickass OP.