Story: Never knew slice of life could be so realistic and beautiful. There is little overdramatic or surprising that happens throughout the series. It's simply about a man in his 30's getting a daughter who is 6. It's heart warming, and cozy feeling. Episodes just fly by without needing to much fluff or drama. It's just the both of them settling in with each other and slowly opening up. One of the most endearing relationships I have seen in an anime. You can't not be happy after watching an episode.
Animation: I loved the style of the series. It's definitely different and has a watercolor look to it. I adored it and love the character designs. It matches the series.
Sound: Nice but not too memorable. It matched greatly with the plot and animation. The seiyuus were just perfect though.
Characters: *I copied this from my manga review about the series because it sums up my feelings for this section* The star contenders are obviously Daikichi and Rin. They are amazing characters who are so realisitc and lovable. They are completely relatable and the decisions they make are understandable. I could see myself in their shoes which is something I don't see in many female orientated series. Also, their relationship is heart warming. One of the most endearing relationships I have seen. They don't lie about their feelings. Daikichi does show how much trouble having a child can be. He doesn't lie about the fact that he made sacrifices for Rin. However, throughout the series, you see how his prospective of her changes into a beautfiul and meaningful relationship. The same goes for Rin. The secondary characters are also given adequate time and development. One of the best things about the series is you can always see where the love comes from. In many female-orientated series (mainly but not limited to shoujo), characters just love each other without you seeing why. There is no question why they love each other in Usagi Drop because you see the reasons clearly.
Overall: Watch it regardless of your prefences especially fans of the manga. It stops right before the second arc which is something I know I appreciate. Also, one of the my top anime series of all time.