Who are some of my favorite tumblr users? The ones who inspire me to get lost in their sites, yeah, those. These sites do include s2 spoilers!
The Final Problem. Sheetlock, the RF Theory that is as enormous as Dear Jim's own network, the Cakebook -- which includes Cake or Death (go read the notes!), you name it; these are all tags on her page btw. Also, if you ever need funnies, go into her tag: Every Sherlockian Family Is Sherlockian In Its Own Way. They are -- as another Sherlockian says -- GOLD.
The Norwood Builder. I keep her site open all the time, actually. I love her Holmes speculation. She marks s3 spoilers really carefully too. *
I Believe in Mycroft. And I love her speculation. *
mystradedoodles. * I have a whole post just on her lovely fun amazing (add more compliments, do!) artwork here. She also does fic prompts. 8)
* Mycroftian and/or Mystrade sources, as well as other Sherlockian goodies.
Favorite SH fan artists would be mystradedoodles (my current mystradedoodles favorites here) and Red Scharlach (my favorites here). Both of them also do Cabin Pressure art too!
If you try my tumblr tag, you'll find more. :) Or get lost in a sea of tumblr, whichever happens first.