So, what are some of your favorite funny cover songs? They don’t have to be intentionally funny (although that’s certainly allowed–and encouraged, even). The songs should also be covers of famous originals.
The Smurfs, for example, cover Glen Miller’s In The Mood. We also have William Shatner singing Lucy in The Sky with Diamonds and Tiny Tim belting out both Stairway to Heaven and Hey Jude.
What are some of your favorites?
Most anything by Big Daddy, but especially “Ice Ice Baby” and “Memory” (from Cats).
I just heard their version of Flashdance. Hilarious!
Shatner does a pretty hilarious “Rocket Man,” too. His, uh, delivery is such that you start to pay attention to how bizarre the lyrics really are. A very zen experience.
The Who’s cover of the theme from the “Batman” TV series.
The Bob’s version of Talking Heads “Psycho killer” is …uh… killer.
The Austin Lounge Lizards do a wonderful bluegrass version of Pink Floyd’s “Dark side of the Moon.”
There are many more (I just burned a disc of “funny cover songs” for a buddy but I am not home to see exactly what I put on it).
Unclviny
Chad Everett of “Medical Center” singing “Ain’t No Sunshine”. It’s on his album called “All Strung Out”.
Ray Stevens clucking his way through “In The Mood”
Pat Boone’s entire album No More Mr. Nice Guy: In a Metal Mood
That album both sucks and blows, but it’s funny as hell.
It’s not meant to be funny, but when I hear Duran Duran’s cover of Public Enemy’s 911 Is a Joke, I laugh and laugh and laugh. 
“Gin and Juice” by the Gourds (Snoop Dogg cover)
“Boyz In the Hood” by Dynamite Hack (Eazy E cover)
Anything by Richard Cheese and Lounge Against the Machine (lounge-style covers of current popular songs)
Anything by William Shatner
I’ve had a few good laughs from “Dread Zeppelin.” They take the old Zeppelin stuff, reggae it up, and use an Elvis impersonator as lead singer.
A few samples over at Amazon.
Dang, both of mine were taken in the last two posts: Richard Cheese and Dread Zeppelin.
Saw them live once on a double bill with Mojo Nixon. Killer show - those guys could really play. Best part was the end, when Tortelvis started handing out scarves {a la Vegas} and glasses of wine {a la gettin’ all liquored up for Mojo}.
The Toy Dolls do a cover of* Livin’ La Vida Loca* using Kazoos that is both hilarious and an improvement on the original.
Cake’s I Will Survive.
Something quite a bit more recent: Weird Al’s cover of Avril Lavigne’s Complicated (it’s called Constipated). I cramped up from laughing.
Hayseed Dixie
Funny when I first heard them. Kinda cool as I continued to listen.
Hawkwind’s cover of the eponymous song “Motorhead”. Somehow funny and good at the same time…
The Folksmen’s cover of “Start Me Up” (originally by the Stones). I can’t even think about it without cracking up. The Folksmen are the fictional group from ‘A Mighty Wind’ but I think it still counts as a hilarious cover.