My favourites were...
Morphin: Especially the orchestra version they used for the Movie. We had this theme for 3 years - how could anyone not like it
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Zeo: As MegaZeo said, a good upgrade of the original, especially the "communicater beep"/Go Go Power Ranger bit at the beginning of the song.
Space: Mainly the music I liked here, but it could have been better IMO.
Time Force: Again loved the music, and the lyrics are actually ok for this series.
Lightspeed Rescue: Took time for me to like this, but it grew on me, unlike the series
The lyrics were quite good this year, and the music is ok too.