Copy+paste from my comment three weeks ago in another thread on here. It got 24 points at the time[1], so I think other people thought it was an example of an enjoyable interview as well. This was for a job for a game development studio that had about 30 employees at the time:
"They asked me to bring in a code sample, we discussed what it did and various details around it, then he showed me an actual class in their codebase (printed out), asked me to explain figure out and explain everything it did, and there was also a couple mistakes included in the code for me to find as well.
The guy also asked me a few relatively simple technical questions, then said "Okay I know you can handle the job, let's see what you really know," asked me some really difficult questions, when I said "I don't know" to some he actually spent a few minutes teaching me the concepts.
That same guy was the lead programmer on some famous arcade games, btw. Did a lot of assembly programming back in the day. He had serious technical chops.
Got a job offer the next day. 1 interview, 1 interviewer, a little over 30 minutes spent.
Best interview experience I ever had. If more interviews were like that I wouldn't feel dread every time I felt the urge to switch jobs."
[1]: https://news.ycombinator.com/item?id=32437818