Mine are
1) Yoru no uta - Tomoyo! Need I say more?
2) Mienai chizu (Invisible Map) - the insert song that is played in the "Sakura, Clow Reed and the Past" episode. I used to listen to this song alot back when I suffered from depression, and it always made me feel a little better. It's so... I dunno. Hopeful, somehow.
3) Hitotsudake - because it's pretty. For some reason it makes me think of Christmas.
4) Yasashisa no tane, Tomoe, and all other songs sung by Iwao Junko - again; Tomoyo!
5) Tobira wo akete - this opening was always my favourite, but I seem to be pretty lonely about it. Everyone else seems to love either Purachina or Catch You Catch Me...