Steve Watson, founder of independent magazine deliver service Stack, is THE source for independent titles. He's always on top of it.
David Moretti, Creative Director of Wired, is well, your source for everything Wired.
Originally the account of mag-fanatic Jeremy Leslie, MagCulture now makes magazines and sells magazines both online and at their brick-and-mortar shop in London, England. A great place to get a glimpse of the newest indie titles.
Rual Aguila is the Art Director at the freshly redesigned Esquire, and he's not shy about sharing!
Keep tabs on what the Entertainment Weekly team is up to.
Leo Jung, Creative Director of The California Sunday Magazine shares piles of great stuff from each issue of the mag.
There's some really great art direction coming out of The Washington Post, and their Creative Director shares some of his favourite stuff on this account.
Chris Clarke—Deputy Creative Director of The Guardian, UK—keeps a fairly regular feed of the best stuff coming out of The Guardian's art departments.
Not all their posts are magazine-related, but it's all pretty great. Their work on Elephant is of particular interest for mag-nerds.
The account of founder/editor of Gym Class Magazine—an on-hold magazine about magazines—Steven Gregor. His hashtag #magloversahoy is also worth checking out!
Jaap Biemans, Art Director at Volkskrant Magazine, keeps this feed full of his favourite covers from around the globe.
Luke keeps a pretty varied account, but his love for magazines comes through more often than not. He's the Art Director behind the beautiful Monotype Recorder.
The daily covers coming from of The Guardian's G2 team.
A studio out of Switzerland that's collaborating on some pretty neat things for international magazine clients.
A new account I'm watching: The account of B.A.M London, a collaboration between David McKendrick (former Creative Director of Esquire) and Lee Belcher (former Art Director of Wallpaper*), who are making all kinds of editorial right now.