The following is a list of known Slender Man blogs. They will be grouped as: Active, Inactive, Possible Blog(s), and Uncategorized. Within that they'll be grouped by the site of which they use. Note that some of them will have other links of which to help follow the series and/or needed to fully grasp the story.
Credit to chasechan2050 for compiling the main list of Slender Man vlogs/blogs which can be found RIGHT HERE.
Normal text: Series is still going
Bolded text: Hit series and/or informative series
Italics text: Series is over/indefinite hiatus
Striked text: Avoid this series
~: Informative series
*: New series/Recently added