The Guinness Book of Records mentions Alexander Woolcott’s broadway review of Wham! which read "Ouch! "
But there is one more dismissive. At the Duchess Theatre in London at the turn of the century there opened a show called A Good Time. next morning it got the simple review “No.”
Just wait until Debbie Does Dallas: The Musical makes it’s debut! Supposedly some of the lyrics go:
[quote]
I’ve seen what he’s got down there
And I’m worried just a little bit.
Though I know I’m strong, he’s oh so long
And I’m afraid it might not fit.
Suck, blow, swallow slow, doggie-style no, no, no!
[quote]
It’s an off-Broadway production! 
James Agee’s entire review of the movie You Were Meant for Me was “That’s what you think.”
I can’t remember the title, but as I recall, the NYT’s entire review for a one-man-show was “The cast was too large.”
Wish I could remember the name of the reviewer or the title of the production (a comedy):
“Laughter was heard at the back of the theater, which led one to believe that someone was telling jokes back there.”
In a 1933 review of the play “The Lake” starring Katherine Hepburn, Dorothy Parker wrote: “Miss Hepburn runs the gamut of emotions from A to B.”
And another from Dorthy Parker, reviewing the play “The House Beautiful”: “The House Beautiful is The Play Lousy.”
Darn, Labdad the House Beautiful one was mine. Grrrrr.
I don’t remember the play, or the exact quote, but one review was the following.