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
Their version of Straight Up is genuinely one of the best things I’ve ever heard.
As for their cover of Goodbye Earl, the only criticism I have is that it’s too damn short.
I love the Gimmes immensely, and am disappointed that I had to scroll down so far to find any mention of them. Their guitarist is in one of the world’s biggest bands ffs!