Jenni Konner: "Girls"
Konner acts as co-showrunner of "Girls" alongside star Lena Dunham (who is, of course, also on Twitter), bringing the experience of having co-created and produced 2009 ABC sitcom "In the Motherhood" and 2006 one "Help Me Help You." She was also a writer on "Undeclared" -- which was how she met Judd Apatow -- and is funny and opinionated, both about the series on which she works (one that generates a lot of opinions!) and other shows she watches.

Jenni Konner

Ronald D. Moore: "Helix," "Outlander"
With "Battlestar Galactica," Moore revamped a 1970s franchise into something dark, compelling and profound that tackled issues of humanity and faith while feeling like sci-fi's answer to the ambitious, gritty dramas that ushered in our current golden age of television. Moore's currently got two new projects in the works, the ongoing claustrophobic infection series "Helix" on Syfy and the upcoming historical fantasy saga "Outlander," and what may be most interesting about his Twitter account is just how much he knows his way around a passionate fandom. For instance, he divided a Twitter Q&A into five questions apiece for each series he worked on, and he's been reassuringly careful about letting the devoted following the "Outlander" novels already have know that the show intends to do right by the story and characters.

Ronald Moore

Ryan Murphy: "American Horror Story," "Glee"
Murphy's currently straddling very different genres with the two series he has on air, one an over-the-top, gory horror anthology show and the other an equally over-the-top high school musical dramedy -- and he also has the HBO movie "The Normal Heart," adapted from Larry Kramer's play, coming out in May, as well as a pilot called "Open," also at the premium network. That busy schedule may be why Murphy chooses not to follow anyone on Twitter, instead using it to tweet out photos from behind the scenes of his two series as well as juicy casting details. Murphy's longtime producing partner Brad Falchuk is on Twitter as well.

Ryan Murphy

Marti Noxon
Noxon's got a few pilots in the works -- "Unreal," at Lifetime, is a particularly interesting one presenting a behind-the-scenes look at the workings of a reality show, based on a terrific short, "Sequin Raze," from Sarah Gertrude Shapiro that made the festival rounds last year. Then there's "Girlfriends Guide To Divorce" at Bravo and Syfy's "Proof," which Noxon co-wrote with M. Night Shyamalan. She's also a TV powerhouse who took over as showrunner of "Buffy the Vampire Slayer" from Joss Whedon in its later seasons ("I ruined Buffy and I will RUIN YOU TOO," notes her Twitter bio), and worked on "Prison Break," "Grey's Anatomy," "Private Practice" and "Mad Men," and she's preparing to direct in 2014. She's also quick to point out the gender imbalances and weirdnesses in the industry and to discuss being a working mom in a realm that doesn't make it easy.

Marti Noxon

Shonda Rhimes: "Scandal," "Grey's Anatomy"
Rhimes isn't just one of the most successful and powerful showrunners working today, she's also a woman of color working in an industry still largely white and male-dominated. On her Twitter account, she brings some much-needed perspective in this regard between sincerely enthusiastic tweets about her two current series that make it clear just how much she loves her job. She directed people to a post about expecting black female characters to be role models, highlighted a video about how the qualities assigned to people change with gender, and her recent response to Mike Huckabee's comments about birth control was a joy. And even if she's on top of the TV world, she's not afraid to confess to staying in to watch some figure skating.

Shonda Rhimes