https://onethingwell.org comes to mind

https://web.archive.org/web/20170608203825/http://onethingwe... - used to be slightly simpler and less colourful.

There might have been few more such blogs over the years but this one has stayed in memory long after I stopped going to it and eventually it stopped (sort of). It was not just the design but also the simplicty of the conent and being very accessible.