Everyones in The Loop

All or nearly all (hey, maybe someone's incommunicado) of the main cast is regularly kept apprised of all important events. If something big happens, everyone knows within a couple of chapters or episodes. No one learns 50 episodes later that everyone else knew his brother was a spy, or that her husband was cheating on her. The characters are actively trying to relay important information and relationships to one another. The complete opposite of Poor Communication Kills. Doesn't happen often due to Rule of Drama, but when it does, the story is usually better for it.

Note that this does not require the complete absence of information that someone is being kept from knowing. If the characters are otherwise making an active effort at pushing info, or not making decisions based on or despite unknown feelings, around then it still applies.

Subtrope of Conservation of Detail. Compare I Know You Know I Know.

Anime and Manga

 * In Eden of the East, everyone is kept apprised of the evolving situation as information filters through. It helps that cell phones are a major part of the plot.
 * In Fullmetal Alchemist, in all versions, the heroes make every attempt to inform each other despite being spread out. There is only one aversion, when the death of Hughes is kept from the Elrics.
 * Notably, Marta telling Al about Fuhrer Bradley in the first anime; as soon as she learns the information, telling him is the first thing she does (which is good as immediately afterward, Bradley ).

Film
"Scott (noticing Wallace, who is passed out but holding his cell phone as if he'd sent a text while unconscious): Wallace, that gossipy bitch..."
 * In Scott Pilgrim Versus the World, everyone knows pretty much immediately about Scott, age 23, dating a high schooler, to the point that Scott tells his friend Wallace, who is drunk and passed out, and not two seconds later Scott's sister calls to yell at him about it.

Literature

 * Katherine Kurtz's Deryni novels The Bishop's Heir and The King's Justice. Many of the characters make regular efforts to invoke Mind Speech over distances to explain where they are on a military campaign, or to keep the ones on campaign up to date on what's happening back home. These efforts are often integral to the plot.

Live Action TV

 * Chuck, usually. Anytime there's a big secret between two characters, it's only an episode or two before it's resolved. The one big exception is Chuck's spy status.
 * Stargate Universe: Maybe it's the close environment, but people on the Destiny don't keep secrets for very long.

Tabletop Games

 * Can metahappen to poor effect in tabletop games when characters already know info before being told or even introduced.