Here are a few to get things started:
Don Henley’s The Boys of Summer as an 80s synth tune
Bossa nova version of Crowded House’s Don’t Dream It’s Over
Reggae-ish version of Aretha Franklin’s Respect
A capella men’s ensemble version of Lady Gaga’s Bad Romance
Imho, Leo is so overrated. All he does is change the instruments used to play the song, and everything else remains the same, including his voice, tempo, lyrics, style, etc.
Now this guy here, is actually impressive, and delivers the cover in different styles.