No Boy No Cry is my favorite too. Just beware, don't go watch the actual video for this song by Stance Punks. It's a bit weird.
No favorite endings, but I liked the cell phone one. I also liked the one where Sakura wakes up from a dream at the end, though it's a little gross with the full body look-over since she's 12.
The little girls in doggy outfits ending was too freaky for me.