The 3rd ED to Cardcaptor Sakura is "Fruits Candy". There seem to be multiple versions of the song, but MAL only lists the one sung by Megumi Kojima. However, I've heard at least one other version (see http://www.youtube.com/watch?v=1uNALWuWJao), and it wouldn't surprise me if there were more. Can anyone confirm what other versions of this song exist and who sings each of them?
According to wikia, there is another version of the song sung by Sakura Tange, Junko Iwao and Aya Hisakawa, the voices of Sakura Kinomoto, Tomoyo Daidouji and Cerberus, respectively. So there are two versions in total.