KON
plus season 2 and movie. Easily the best anime ive ever seen and its not even close.

I should mention that i technically enjoy clannad and clannad after story more, though thats an adaptation of a visual novel and i tend to exclude them from lists of favorite anime

Is the manga still ongoing? I was caught up at one point like 2-3 years ago (right up until whenever Yona almost died but the kings shield power or whatever it was saved her or something, but waiting however long it was for each chapter with how short they were really drained me so i stopped and planned to come back to it once it finished.

Yona deserves to be talked about more, though with only one season I guess it was inevitable that it didn't become too big. Unless you're AoT, one season just ain't enough to gain the popularity to last longer than your run time

KON
more specifically, the second season, but S1 i love just as much

For me personally, a masterpiece just needs to sufficiently impact me as a person or have extremely well done emotional bits, even if its not the most well written thing outside of that. Either that, or the narrative its telling has to be complex while remaining specific and consistent while delivering through to the end. For an example of the first kind, AIR, particularly the visual novel by KEY Visual Arts. It has a lot of problems, some of them glaringly obvious, but the emotional strength of the main route and its follow up routes is more than enough to make up for it and for me to consider it a masterpiece. For an example of the latter, Attack On Titan. AoT managed to consistently build upon its originally simple (though already unique) premise with each passing chapter, reveal, and interaction, creating an extremely complex world with a strong narrative to back it up. The few problems AoT does have are easily overlooked and ignored because of how well executed everything else is for the most part.

forgot to mention but GT can be watched any time after kai 2014. its not canon technically (who really cares though) but was the original Z sequel

DB
Z/Kai
Kai 2014
Super

Kai is basically just Z but with most of the filler removed. Watch it instead of Z if you want pacing that wont make you a danger to yourself

I should also add that Clannad definitely fits the "ponder about your life" description, especially for me, and that becomes even more true the older I get.

Though I hate the fact that Clannad + After Story is simply labeled as "sad show" and nothing more, it definitely is the most emotional thing I've ever experienced, and the VN is my favorite thing of all time, though the anime adaptation is pretty great and is worth watching if you're not a VN reader.

Another recommendation is K-On because I am legally required to mention it in every comment I make on anilist. While not a sad show by any means, there are two episodes towards the end of its 40 episode run time that are second only to Clannad in how much they break me emotionally. 99% of the show is happy and fun, but that's what makes those two episodes so especially emotional.

To answer your Clannad question specifically (since i am in fact the world's biggest fan of this series), while its true that Clannad After Story is better than the first part of the series, I personally like the first part just as much. Partially because it's necessary for AS to mean anything at all, but also just because its genuinely enjoyable. If you don't like slow and boring SoL stuff it might be a bit of a slog to get through but its not something thats skippable.

With that said though I think Clannad deserves more than just the "this anime is so sad" label that it often gets reduced to. The first part of the show won't have you feeling very much for the most part outside a few scenes here and there that might hit if you get particularly attached to one of the characters, but if you take it for what it's supposed to be, a SoL drama with some comedy mixed in, instead of just viewing it as "the boring stuff before i get to cry", it becomes much more fun to watch.

Love Live is so average that I despise it so i guess that counts

I hate the word overrated but I really cannot get into Nichijou despite the large amounts of praise it gets from people who like certain genres. Ive tried twice now, the first time i didnt even make it past episode 0, and the second time i skipped episode 0 halfway through but dropped it again after episode 1. Slice of life is my main and favorite genre but Nichijou episodes feel like they take an hour a piece and are just not entertaining enough to justify that

if memory serves me right, i watched from episode 9 of DN to episode 25, i think. thats not much for some people but its the most ive ever done in a day. was only possible because death note is super bingeable up until episode 26

i think you largely miss the point of kyoani works, though it seems to just not be your style, so fair enough

As a KyoAni stan in the making, may i ask why?

Love Live is so incredibly mediocre (and therefore boring) in every regard that i'd rather watch something genuinely bad just because it would be more entertaining

i read the manga awhile back and i agree with a lot of this. ive heard that the manga is better than the movie version even, so thats saying something. the drama felt super forced and fake to me. i couldn't get invested at all, since it felt like one of those things where youre expected to be sad and upset just because you see that the characters are.

I did that after watch 4. I refuse to accept that K-On ends.

Im on the same watch number currently. I watched it for the first time in February and its had me obsessed ever since.

I agree with you in a way, but to say that neither of them are villains is to also say that both of them are. Just depends on what perspective you view it from.

That being said I do think words such as villain don't technically work, i just needed an excuse to say something AoT related as its been awhile since ive done so