If wanting to listen to only one selection, I'd start at 1:33. But it's also recommended from the start as well.
And while this second one doesn't have Shatner actually doing the vocal, it's an homage to his style and can stick in the mind in a strange way. It's better viewed way late at night -- 3 AM may be about the best time:
I would suggest starting at 0:41 to save time.