Just finished Overlord, here's my top 4!
Wanted to do top 5, but the Venn would be too crowded.
Overlord is peak power fantasy writing to me. Other isekais only tells you what the impact of the protag has on the world, but Overlord meticulously builds its world to show the impact. Classic show don't tell, but 90% of isekais out there would rather go with "Yay I obtained skill XYZ let's go show off" for some reason.
I enjoy the politics and dynamics of the world. The more detailed the status-quo is, the better when protag came crashing through. How they dealt with the Kingdom and Empire was excellent. Holy Kingdom was a bit iffy for me, but oh well.
I'd have to say, there is quite little character development in this series. It's also hard to care about them when they're either dead, eventually dead, or obsessed with the protag. I want more people like Emperor Jircniv!
The last few volumes was enjoyable but disappointing in terms of plot, especially when there are only 2 vols left. Oh well, better end than becoming another GRRM.
FOR COMPARSION! (just wanna gush, bear with me)
I think Overlord has high quality writing, on par with Bookworm. Most fantasy LNs have shit writing tbh, but these titles are full fledge novels lol.
I wish Overlord could have imitated the feeling of hopelessness for the victim nations like in 86, or the high intense atmosphere for its large scale fighting like Tanya and 86. But then again, orange and apples. I can only wish haha.