I started watching K-On recently, and I'm honestly surprised by how great it is. I've never been a huge fan of moe, and since K-On is widely considered the show that made CGDCT a juggernaut, I'd always figured it'd be some sad otaku-bait mewling loli-fest. Never have I been more glad to be proven wrong.
The show's pretty heavy on the moe, but there's a certain subtle, fascinating undercurrent of realism running through it as well, from the tiniest of gestures to the shortest of dialogues. Everything that the girls do radiates individuality, and while they're all firmly rooted in their respective archetypes, there's also just enough interesting contradictions and one-off quirks to give the whole show a sense of authenticity. Don't get me wrong, it isn't Boyhood with Japanese girl bands, but it tempers the cute highschool fantasy with a wonderful layer of verisimilitude, always keeping the interactions fresh and relatable.
The show apparently accumulated a huge female fan-following, and I think it's because it excels at balancing a fairly authentic cast with the whole 'sparkling, never-ending girls' school life' gimmick. The director, Naoto Yamada, has a gift for making the characters seem cute without being saccharinely kawaii, and the whole show just thrums with so much life and momentum. It isn't high art, but it's the most fun I've had watching anything in ages (and it certainly healed my Omoide no Marnie trauma).
I'm only around 10 episodes into season 1, so there's gonna be some fun times ahead. Also, the ending theme is the most catchy song I've heard from anything that's not Touhou.