Noir - episode 6 (aka 'Lost Kitten')
This show just absolutely breaks my heart. Kirika has to be one of the saddest anime characters I've ever seen - she's like Rei Ayanami on downers, and all without her barely doing a thing. And the funniest thing is you just know if this show was made today, it'd be fanserviced up to the hilt with the whole Kirika/Mirielle relationship thing. I just love the visual styling of the show - it's not afraid to take things slowly, and the English dub is really well done, as is the soundtrack - you can really tell it's a Yuki Kaijiura work, the choral battle theme feels like a natural precursor to Mami's theme in Madoka Magica. Also, the Ali Project OP totally rocks.