There are far too many good tunes around to have only the one.
So I would have to say that the top 10 should consist of at least one of these fine tunes

    King of Nothing by the Kevin McDermott Orchestra
    What comes to pass       "            "
    Going Home               Dire Straits
    Loch Lomond             Run Rig
    Yellow on the Broom      Adam McNaughtan
    I Can Feel It            The Silencers
    Always look on the bright side of life
    Immortality             Celine Dion
    You wont listen          The riverdetectives
    Perfect Gentleman       Wyclif Jean

as i said far to many songs left out so this. I ll probably come back later and add a few more but hey thats the whole point in having an oppinion
Cheers