Well I figured I would start a new cool threat where people could share their worst job interview experinces.
I guess I can start with one of my worst.
I go in for an interview for a local large medical clinic and the position was a Support Specialist position, I was informed by the staffing agency that there would be a group interviewing me of 2-3 people. So I agree that it's fine.
I go in that day and go to the lobby and I'm perfectly on time wearing my favorite tie, got to add in the tie part, that’s critical!!

Then inform the receptionist that I'm here for an interview with such and such. She calls up the guy and informs me to sit in the waiting lobby.
Yep, I go sit down and waited 3-4 minutes so I figured I’d get out my laptop and browse the web. 30 Minutes later I go back up to the receptionist and ask her to page such and such again, and she tells me he’s on his way down, so I sit back down and wait another 5 minutes till he finally comes to gets me.
We go up to the top floor of the building where they are still doing construction, dry wall dust everywhere from dry walls being tore down, poor lighting and the carpet looks like it’s never been vacuumed. I had to get my suit dry cleaned after that interview.
He takes me into a large meeting room with a table about 12 feet long with like 14 chairs at it. So I sit down and I realize that it’s about 104 degrees in the room, within minutes I'm sweating like a pig. After I start sweating he informs me "oh we have an air conditioning problem"
go figure!!
He tells me to wait a few minutes for the rest of the group to come in, after waiting 5 minutes about 6 people crowded in so 7 people were at the table plus me. Right when we are about to start one of the guys wife calls and they are on the telephone for over 10 minutes talking about their son having the flu. So we finally start after an hour waiting and they apologize for the wait.
After talking for awhile discussing my resume and my previous experience in hospital information services they start asking me questions on how I would do stuff. Every answer I provided them apparently violates their IT policy as well as the position I was interviewing would not give me the resources to do the required work in the quickest, most efficient way.
At one point in the interview I go to answer a guys question and right when I start to answer another guy adds to the question then just starts to yell at me for interrupting him while trying to answer the initial question.
Right after that I got up, grabbed my laptop bag, threw it on my shoulder and looked at the guys and said something along the lines of;
"I come in here expecting 2-3 people and the whole IT department shows up. This interview was supposed to start at 10:00 and it’s almost lunch time. It is way too hot in this room and I now have to get my suit dry cleaned because this place is a nasty mess. I will NOT be yelled at by anyone whatsoever with that being said, please do not bother contacting me. I will be informing the staffing agency about this interview. I appreciate your time gentlemen, have a nice day”
SCORE!! Walked out while they were still stunned.
Needless to say they didn't call me

and later heard that the staffing agency cut off all ties with the company.
The staffing agency reimbursed me for dry cleaning expenses.