Despite the melodramatic Ohana + Kou angle, Hanasaku Iroha narrowly eeks out Usagi Drop as the best Summer 2011 show by turning the inn into a character. Love Hina did the same thing, although I didn't notice it until the Hinatasou reappeared in Earth Defender Mao-chan; I realized I missed the inn itself. As for Hanasaku Iroha, it is disappointing that the tensionless romance between Ohana and Kou was so uninteresting, but every other aspect of an otherwise engaging show earns it the top spot.
Usagi Drop likely would have fared much better were it longer than its mere 11 episodes. Every episode was good, earning it the No Bad Episodes award, but there simply needs to be more to the show to make it a solid series. With only 11 episodes, it's practically in OVA territory. Then again, perhaps it would not be better served with additional episodes. I know there are controversial events following a timeskip resulting in a widely disliked ending. Although I have a general understanding of these spoilers, I have not read the manga itself so I cannot speak for their execution. If the events are done well, perhaps more Usagi Drop episodes would make the show even better. If all they're going to do is antagonize most viewers, then maybe it's best that Usagi Drop ended when it did.
The IDOLM@STER succeeds by taking simple things and doing them very well. It also help that it has a deep cast of charismatic characters, allowing the viewer to latch onto his favorites. Ahem. Chihaya > Miki > Takane > Makoto > Ritsuko > Mami > Hibiki > Ami > Iori > Azusa > Kotori > Haruka > Yayoi > Yukiho. I am a little troubled by the slightly knobby faces, but they never cross into K-On! territory, so I'm satisfied.
I'm treating the Magic Kaito / Kid the Phantom Thief episodes of Detective Conan separately. Not quite a spinoff, and not quite OVAs, they aired in the regular Detective Conan timeslot to focus on the titular long-time Detective Conan side character before crossing over with the Detective Conan series proper. These episodes were very good, although I'm not sure how they fit into the canon. I'm a little confused as to the timelines and the ages of the characters involved, but this might be because there are large gaps in my list of watched Detective Conan episodes. Fujimura Ayumi does a really good cranky voice as Aoko, too.
Suite Precure♪ has been mostly good, benefiting from a well-done Cure Beat arc. Although I'm opposed on principle against [spoilers] making non-human characters bona fide Cures, I guess I'm okay with it since Ellen is stuck in human form and hasn't been able to transform back into a cat (or anything else). I'm hoping the Cure Muse episodes are as good, because right now I find Cure Muse hopelessly uninteresting. Worst Cure ever.
Dantalian no Shoka should have been better, but could have been worse. It's not much of a series, ending abruptly at 12 episodes, but it had enough good moments interspersed throughout to make it the anime equivalent of a collection of short stories. I did want more episodes with the fireman and Flamberge, though. Koshimizu Ami played Flam exactly the way I picture Marisa from Touhou. (I don't actually know jack shit about Touhou). I still don't know why Flam wears a straitjacket dress, though.
Detective Conan is Detective Conan, but if you leave out the Kaito episodes mentioned above, this was actually a relatively weak cour of episodes—enough to knock it down a bit, whereas the average Detective Conan cour would typically be above Suite Precure♪ and Dantalian no Shoka.
Dropped shows: I dropped Uta no Prince-sama - Maji Love 1000% after one episode because it didn't interest me. I considered watching a second episode for a long time, though. Likewise I dropped Nekogami Yaoyorozu after one episode semi-reluctantly. After all, it did star HOCCHAN and Haruka Tomatosauce, but I couldn't bring myself to watch more of it.
Kaito Tenshi Twin Angel - Kyun Kyun☆Tokimeki Paradise!!, at least the one episode I watched, was WORSE THAN COSPRAYERS. I only watched the first episode at all thanks to Asakawa Yuu's constant pimping of her new show on Twitter, but it just wasn't very good. Very likely it had a good episode or two somewhere down the line, but I wasn't sticking around to find out. If someone watched it all and can identify any must-watch episodes of Kaito Tenshi Twin Angel - Kyun Kyun☆Tokimeki Paradise!!, send me a telegram.