It's too many I can't pick the best among all of them..>_<
Naruto - almost all of the opening and ending
Cardcaptor Sakura - all of them!!
Inuyasha - Change the World, Dearest
Gakuen Alice - op. and end.
Chobits - Let Me Be With You
Paradise Kiss: Lonely In Gorgeous
Gunslinger Girl - the light before we land
Gun x Sword - op. and end
Tsubasa Chronicles - op and end
It's too many...I can't write anymore!!