Stuff that you're really in love with and enthusiastic about! Could also be used to describe acts of affection like a guy buying roses for a girl.
"That's Passionate Shit mate!" (Guy being played a tune he likes a lot)
"Flowers, Chocolates? I don't do all that Passionate Shit" (Guy explaining that he isn't the Romantic type!)
The Cheek of Her (Music Artist) has an Album called "Passionate Shit" (This entails that the music is full of passion!)