I totally agree with you, mate. Choosing one favorite is VERY difficult for me as well!
This is my list:
Heart of the flower
Peace on earth
Sounds like a Melody
Upside down
Lassie come home
Inside Out
Point of known return
Dance with me
Change the world
Miracle Healing ( CROAG)
Euphoria
Romeos
Danger in your paradise ( United)
For a milion
Mysteries of love
Heartbreak city
Duel
Soul Messiah ( Salvation)
Spirit of the Age
Carry your flag ( All versions)
New Horizons
Lies
The Jet set
Feathers and Tar