I had one with Game Closure. They flew me out to their offices after being impressed with a game I made and made it seem like I was basically granted a job, and an interview was a formality (admittedly, this did result in me slacking a bit and I was a dumb young college student with a bit of pride). The interview was purely high-level mathematics and algorithm questions which I wasn't prepared for, they said they'd be willing to pay $40,000 a year (that's nothing in Silicon Valley), and everyone was just kind of horrible. Then the CEO walked in, endlessly berated me, and honestly said I'm a fraud and a liar and I can't program. I laughed when they gave me the rejection call a week later and said they'd be willing to call me back if a new spot opened up, because really, it's preferable to just skip on the formalities after calling me a fraud.
The only thing that really did bother me was two engineers showed me a game they were working on and asked me what I thought. We talked a bit and I ended up giving them a bunch of "here's what I'd do to make the game more fun/interesting" ideas, and everything I mentioned was at some point added to that game (these were fairly basic concepts such as level designs, so it's possible they had some thoughts on their own). I learned never to give advice to a company without compensation, at least.
The only thing that really did bother me was two engineers showed me a game they were working on and asked me what I thought. We talked a bit and I ended up giving them a bunch of "here's what I'd do to make the game more fun/interesting" ideas, and everything I mentioned was at some point added to that game (these were fairly basic concepts such as level designs, so it's possible they had some thoughts on their own). I learned never to give advice to a company without compensation, at least.