Unfortunately the offers weren't exactly pouring in for me, so I took the job, and you know what? It was just like the interview. People were bored, there wasn't much going on. Nobody was passionate about the decades-long process involved in making a power plant. The best part was when they told another intern to make a department website, he'd never even heard of such a thing and didn't know anything about websites so they got him some books to read about HTML.
Luckily, I only wasted a summer internship on that mistake. But it taught me that you can, and must, learn a lot a from a job interview... in this case I learned from the interview that no one at the company was excited about talking about what they did, and didn't care much to listen to people. It held true after the interview.
I'm an engineer. I thought there was no reason for me to care about people. But the fact is, engineering is engineering everywhere. My whole life it's going to be connectors, wires, electrons, and getting the right blinky lights to light up. I like the work and it's satisfying but the only thing that makes one job different from another is the people that I'm going to work with. They have to be cool, and they have to care.
So anyway, I don't know what your #1 question is to ask in an interview but here's mine:
What do you love most about working here?
The answer I'm looking for is "It's a great group of people." Because even though we all go home and watch reality shows about competitive people screaming "I'M NOT HERE TO MAKE FRIENDS!" that's not how I want to spend my day. I am, actually, here to make friends. Meet for a drink later, go out for lunch. Like each other.
If they stumble and then mutter something about the 401K matching, I know to run screaming. The healthcare package should not be your favorite thing about the company you work at... that should be a given. It's like dating, I've told girlfriends that they can't stay with a guy just because "he's really nice". that's a baseline requirement. In a world where you only get to have one boyfriend at a time, you have to raise the bar... and I'm only going to have one job at a time.
I'm not interviewing for jobs now. I am interviewing people to hire, sometimes, and that's what gets me thinking about this. I try to ask them their stories, find out how they connect with other humans. Our HR department filters out anyone with a GPA that's too low, I go in assuming that the person in the chair is smart. But I want him to be the kind of engineer who gets to know the technicians on the line, calls meetings with the certification experts, gives the buyer a heads-up that we need a different part number in a few weeks.
I look at the person I'm interviewing and think sure, I can teach you to make airplanes. But you have to be something else: YOU have to be another reason for me to enjoy working here. I can't teach that. You have to show it in the interview.