I would love to have the ability hear an obnoxious cell-phone ring and then reproduce it flawlessly.
A friend of mine can do a siren - as in police/fire - perfectly. He’s cleared a bar with people running outside to see what’s going on. I think that’d be kinda cool.
The sound of one hand clapping.
Either that, or a really wet fart.
I can do a passable Blue of Blue’s Clue fame. One of the little side results of motherhood, I suppose. (There are a surprising number of mommies who claim to be able to immitate Blue.)
I would much rather be able to talk like Katherine Hepburn or sing like Sarah Brightman. That would be so much cooler. and sexier. Blue is just not a “bedroom” sort of voice.
Either a really, really good evil laugh, or Renée Fleming, either one is good.
Chris Cornell. And it really doesn’t even need to be explained.
I wish I could make realistic fart noises without any smell.
My friend Georgie. Or Stockard Channing. They both have incredibly sexy voices.
I always thought it would be great if on a hidden camera show the cast of The Simpsons (Dan Castellaneta, Julie Kavner, Nancy Cartwright, & Yeardly Smith) went to a Denny’s and got a booth adjacent (but not viewable) to other customers and started a typical family quarrel with their Simpson voices.
- Foghorn Leghorn
- The Seiyuu (voice actor) for Hitsugaya Toushiro on Bleach.
- Ultra-realistic female orgasm sounds.
Ah, Michael Winslow. Man of a thousand sounds, each and every one incredibly annoying. 
See post #12.
It’s ok with me if you want to kill everyone in the room and bring down the roof. 
I’m not quite so ambitious.
As I naturally sound like an overly ambitious 8 year old girl, I am going to say Kathleen Turner or someone similar.
That crossed my mind earlier as being handy if your on a lonely street late at night being approached by a gang of muggers.
But the one I can actually do is perfectly reproduce the challenging yowl of a tom cat when it sees another tom on its territory.
Which could be useful if ever I decide to become a burglar and knock a trash can over
but otherwise not very useful at all.
Andrew Eldritch.
It would sound really weird coming from the 117-pound guy with JPop hair, but I’d be OK with that. Matthew Sweet (at least on Delerium’s “Daylight”) would probably sound more congruous, and I wouldn’t mind settling.
If I could do more than one tone at once, a grand piano.
His name isn’t Lenny, is it?
I can do some celebrity impersonations but that doesn’t satisfy me. A high school classmate used to do a spot on Donald Duck voice. I asked her to teach me but I never could get it right. My throat would get irritated from trying so hard and I was so envious of those who could mimic the voice with no problems.
You know that monotone beeping sound that was heard in the movie “Silkwood” whenever someone got contaminated with plutonium? I’d love to mimic that sound when I encounter very rude people. “Sorry, hon, you need to go to the showers now. Guess you’ll remember your manners next time”.