The Mansion of E by Robert M. Cook is found here:
This is a webcomic that has run for years, I believe it began in 2005, and I think I have been reading since about 2008.
It’s slow-paced, and though the esthetics are improving along the way, I think it is safe to suggest that it is about world-developing more than it is about art.
Which works fine by me, because the world developed and it’s characters are interesting and believable in their own way.
There is a sort-of plot, which is perhaps better described as a setup, but this serves more to illuminate the cast, which has grown rather large throughout a decade (!) of consistent updates.
The creator is also making a significant effort in tagging character’s latest occurrences and seemingly tying the many storylines somewhat neatly together, which I personally has found very useful.
I find it hard to pinpoint exactly what it is about MoE that makes me keep coming back, and I believe it is highly subjective. Taking into account the art and the slow pace of the story it might well be one of those things that you either love or hate.
Speaking for myself it is by now a regular part of my morning routine, and I enjoy the feeling of freedom from it; the ability to explore the facets of the story as they turn up, the progress of building a very complex world while keeping your own pace and (I think) enjoying the experience of doing so.
Also, I like the characters. Quite simply.