ATP World Tour: The ATP does a commendable job using its access to produce valuable and exclusive content on its website. Its Twitter account keeps you in the loop.
WTA Tour: A good one-stop account to keep tabs on the WTA.
Australian Open: The best social media account of all the Slams. You may need to unfollow for 10 months of the year given their penchant for non-stop tweeting, but it is still the shining example of how to run a tournament Twitter account.
Wimbledon: Just as good as the Australian Open account and far less invasive on your timeline.
French Open: A must-follow during the tournament, which starts May 19.
U.S. Open: The account gets sponsor-heavy during the tournament but they tweet immediate hot shot clips, which make it an invaluable follow.
Davis Cup: Incredibly helpful on Davis Cup weekends when multiple ties are going on all over the globe.
Fed Cup: See Davis Cup.
Greg Sharko: The ATP's resident stat czar.
Kevin Fischer: WTA Director of Communications and resident stat czar.
Roger Federer: There's just something incredibly endearing about it all.
Maria Sharapova: After a slow start, Sharapova really brought her A-game on Twitter in 2014. Amusing and self-aware, though you have to ignore the spurts of Sugarpova propaganda.
Serena Williams: Because you never know what you're going to get from the No. 1 and living legend. And that's the fun of it.
Stan Wawrinka: Wawrinka actually doesn't tweet a ton. But he retweets all the good (and bad) tweets about him and interacts with players, fans and journalists. His self-deprecating sense of humor really shines through.
Caroline Wozniacki: Aside from being funny and cheeky, Wozniacki seems to be the hub of the tennis social network.
Andrea Petkovic: Tennis' equivalent to Williamsburg, Brooklyn -- too cool for school and very entertaining.
Laura Robson: Tweet for tweet, there is no better tweeter in the tennis Twittersphere.
Alison Riske: The American's Twitter skills far outpace her current ranking.
Madison Keys: Not unlike Robson, Keys's sarcasm and self-deprecation offers a window into her personality.
Andy Murray: He doesn't tweet often, but when he does, he delivers.
Novak Djokovic: His tweets are earnest, which belies his jocular nature, but also informative.
Eugenie Bouchard: If selfies are your thing, Bouchard has you covered.
Flavia Pennetta: You can brush up on your Italian while keeping track of all of the always-entertaining Italians.
Jelena Jankovic: Just scroll through for five seconds and let the Jelena Jankovic-ness of it all wash over you.
The News Breakers
Matt Cronin: The tennis beat-writer and breaks news regularly on Twitter.
Christopher Clarey: The chief tennis correspondent for The New York Times.
Doug Robson: In the tennis trenches for USA Today.
Tom Perrotta: Tennis writer for The Wall Street Journal.
ESPN Tennis: They now have the television rights to all four majors and continue to air (usually via online streaming) hundreds of tour-level matches.
TennisTV: One of the wittiest corporate accounts in tennis, TennisTV is a must-follow just for their timely screencaps, match coverage and highlight clips.
Tennis.com: With Pete Bodo and Steve Tignor as the core of their writing team, the account is a must-follow.
BBC Tennis: Our friends across the pond keep you up-to-date on all tennis stories, big and small.
Ben Rothenberg: A freelance tennis writer and regular contributor for The New York Times, Rothenberg has a passion for finding the under-the-radar stories. (Disclaimer: He's also my co-host on the No Challenges Remaining Podcast).
Darren Cahill: The ESPN commentator and Adidas coach offers a lot of insight and fair and balanced analysis, even when he's off the air.
Simon Briggs: The chief tennis correspondent for The Telegraph U.K. is great source for breaking news.
Simon Cambers: British freelancer who always has a finger on the pulse of what's going on.
Colette Lewis: The go-to resource for all things junior and college tennis.
Carole Bouchard: The bilingual French journalist's informative and amusing tweets show a true passion for the game.
Kamakshi Tandon: A contributor for ESPN.com, Tandon doesn't tweet often. But when she does they're zingers.
Nick Lester: The tennis commentator offers grounded tennis analysis and, when he's on site, breaking news.
The Best of the Rest
The Changeover: Everyone involved with the blog deserves a follow. Plus it's a great source for tennis gifs.
The Tennis Island: The brand new blog just started this year with two very knowledgeable (and must-follow) young fans, David Kane and Victoria Chiesa, at the helm. Their team of contributors feature some of the wittiest fans on Twitter, all of whom are worth following.
PseudoFed: Still the GOAT of parody accounts.