Some of these stories here are really fun, let me share one of mine, even if it is a bit long.
I don't have an exceptionally high-end rig, but it's generally more than what most people would want to spend on audio.
At the time of this story I still owned a Asus Xonar STU and a pair of Hifiman HE-400s. Now, this was a few years ago, when I would spend a lot of time at the office, doing overtime, going to an average of 15 hours of work per day, so naturally, I bought my stuff along and a flash drive with a lot of FLAC music.
A colleague of mine saw them and said that they looked "fancy" and asked me how much they're worth. I tell him how much I spent on them and he was shocked, he picked up our company standard issue AKG K-66 and waved it around, saying that "It can't possibly be much better than this, it's just a headphone!".
Oh my, while I respected my colleague, we knew each other for years and called him out on being a dolt and he was dumbfounded. He figured out that I feel this strongly about it, then there must be something there. Not necessarily something that makes sense, but something indeed.
So I tell him to come by my department after 6, when only a few of us were left (I didn't want to bother people, since the HE-400 are open-backed).
I let him sit in my chair, power up to ol' STU and connect the headphones and tell him to go wild, while leaving the FLAC music folder open on the PC. Yeah, he didn't really get that Foobar icon, so he ignored the folder and went directly to Youtube for music. I wanted to interrupt him, but I thought it would be a good enough opportunity to demonstrate the differences between Youtube quality and real quality.
So I asked him to pick a track which I already had as FLAC and listen to it on Youtube, then I told him to listen to the FLAC. He was surprised by the difference between the two, but he wasn't that impressed with the overall quality.
I thought to myself "Hmm, this is not the reaction I expected... Let's try something else", I assumed it was not his type of music, but truth be told, I didn't have much else on the flash drive except for blues, jazz and a bit of classical. I didn't know what his musical preferences were, but I thought that he maybe was into EDM or hip-hop or something. Playing them off Youtube would have been in vain, but still he gave it a go and agreed that the combo sounds good, quite better than the standard onboard audio and AKG K66, but not enough to be worth the money.
I did not agree, but I respected his opinion. I was defeated, but there wasn't really anything wrong with that, we had agreed to disagree and there was no harm in it... Except maybe my slightly-bruised pride.
The next day, I had a bit of an idea, I thought that if he didn't really like my music, maybe there was another way to convince him of the quality of the audio.
In our studio we have a foley artist who is an exceptionally talented individual and also a really nice guy and asked him to put together some sounds in there for me to help me showcase depth, soundstage and the various advantages of a well put together presentation (now this guy knows audio and his office is sound-proof and full of high-end gear which I will never be able to afford). So a few hours later he gets back to be with a binaural compilation of various sounds. There was all kinds of stuff in it, rocks falling, bowling balls rolling, dried mud being scraped on, glass sounds, plastic sounds, a whole lot of crazy stuff), but the kicker was that it was all uncompressed. The file that only had a few minutes was 192k/24bit and it had 2.2 GB.
So I call the first guy again to my desk, ask him to put on the headphones and to hit play. He was skeptical and very smug, being sure that I wouldn't be able to change his opinion, so he complied.
He first hears the rocks falling onto a hard surface. He immediately pauses and asks me "What was that?! What is this?" and I tell him to go on with it. He stays still for a second, surprised, but I couldn't tell if it was good or bad. He keeps on going, I watch his reaction change from one sound to another. He got to a point where he was moving anxiously in the chair as the sound of tape being rolled around him went round and round, as well done binaural audio does.
At the end of it, he pushes the headphones into me, almost like wanting to hit me and asks "Sooo, how much did you say these were again?". I tell him and he replies "Aha... Do they come in a version that won't wake my wife up?".
So now he is the proud owner of a Asus Xonar STX, a pair of Sennheiser HD600 and another pair of Sony MDR-1R.
Needless to say, he doesn't use the K66 our company issued us.
So, yeah, that's my favorite story, sorry if it's too long. Hope you guys enjoyed it as much as I enjoyed reading yours.
Have fun and keep on spreading the joys of hi-fi audio!