When this anime first came out, I didn't give it a second glance, to be honest. I read the synopsis - didn't find it interesting at all. Then, about a month later, I started seeing gifs of it (of Oreki), then I said: "He seems like an interesting character, okay, why don't I give it a chance."; then I started watching it in June - fell in love with Oreki from the first episode.
Story: There really isn't a story. After they solved the "Hyouka" case, they just solved the mysteries that happen around them. Nevertheless, I enjoyed every minute of it. I really like the mystery aspect of it.
Art: Beautiful. That's the only word I have for it. The scenery, characters, everything. I also liked how stylish the characters were, also, if that's considered "art."
Sound: Awesome. I loved both of the openings and endings.
Characters: All of them were interesting in their own little way. Houtarou is my favorite character though; he's just so relatable and, lets not forget, handsome. Then there's Satoshi - I just love his personality, and he's cute. Mayaka; there isn't anything special about her in particular, but I didn't dislike her. Lets not forget the overbearing, annoyance - Chitanda. Lol, but seriously, in episodes 1 through 5, I think, I found her extremely annoying! But thankfully, she gradually began to ease up, in my opinion.
Enjoyment: Looked forward to every episode. Really enjoyed watching how they went about solving the mysteries - it intrigued me.
Overall: Anime is subjective. Just because I really liked it, doesn't mean you will.