‘Say something!’ (source: pixivid 2683511)
The general rule of browsing anime is that you give them one episode to hook you, then three episodes to impress you. If there was something amazing a series was going to do, then three episodes is plenty of time to do it in. And, perhaps knowing this, if an anime is planning a shift in tone, a surprising twist, or an early spike in tension, then episode 03 is when they usually execute it.
The Kantai Collection –KanColle- anime has adhered to this convention, and since I did intro it over on Random Curiosity I thought I should say something more about it.
Spoilers for the KanColle anime and Puella Magi Madoka Magica after the break.