#15 Angel Beats OP
My Soul, Your Beats - Lia
Beautiful opening animation to an amazing song. Key simply has an odd habit of using stills to introduce the characters in their theme songs -- that's the only thing keeping the opening animations from really standing out.

#14 Last Exile ED
Over the Sky - Hitomi
The beautiful imagery and equally ethereal sound are a perfect way to wind down after an episode. Again, the only thing holding this back from matching up with higher entries in the list is the stills.

#13 Samurai 7 ED
Fuhen - Rin'
Brownie points for the song, but the actual animation also subtly changes throughout. A great match for its series.