A Southern United States phrase; it usually shows disgust or suprise with a situation or person.

Because the phrase tends to be used by itself, many people in the North US who hear it think that the speaker has not finished their sentence.
A, Southerner: "That Joel; I tell you what."
*a few seconds pass*
B, Northerner: "... What?"
A, Southerner: "I just TOLD you!"
by Leilani_h June 4, 2005
chiefly southern, esp texan. added at the end of pretty much anything, esp to add exclamatory sense to a clause. has a somewhat cryptic meaning known only to southerners. so you non-hicks, stop trying.
by yuan January 6, 2005
A phrase commonly used by people in the South. Can be used in the beginning or end of a sentence. Common to Texans, it is used as a whole sentence, with nothing before or after it.
Bill Engvall talking about Texans: "Man, I tell you what."
"What?"
"I told you."
by Nicolee February 8, 2012
Something Gary Whittaker says to either begin or end a conversation.
"I tell you what, that beagle is a power dog." - Gary Whittaker

"I tell you what, one time I ate 5 gallons of ice cream in one sitting" - Gary Whittaker

"I was at one time, the fastest man in Ohio...I tell you what, was the fastest white guy down at state." - Gary Whittaker
by Maynard Yoh February 7, 2012
Saying originating from Belmont County, OH. Used to begin a story or after something that promotes bragging rights in a rural or backwoods boondocks area. A similar saying is That's what's up.
Ex. I put a 3" lift kit and some 31's on my Chevy Tracker the other day, I'll tell you what and such.

Ex. I caught a catfish the other night. It was a big'un, I'll tell you what and such.
by ovredneck69 June 22, 2014
By the use of this phrase to open or close a statement, the user acquires or asserts a pleasant, folksy authority. Sometimes paired with "boy" for added authority and folksiness (see example).

Frequent famous users include Cris Collinsworth and Hank Hill.
"Boy, that was a heck of a down field block by Michael Vick, I tell you what."

"I tell you what, the Seattle Seahawks came here to play tonight."
by TebowTime23 January 20, 2012