First real headphone I had was the Koss TNT/55. They were usually sold by Radioshack for $40, but nearly always $20. Labeled as a Realistic or some other brand.
Pretty impressed by how they sounded out of a tape player. Yes, back then we all used tape players! I think this was when I was anywhere from 13-16. I'm now 31.
Back then most people used the headphones that came with their CD or tape player.
Next good headphone was not until I was 18. Got a Bose Triport AE1. Always loved it back then, but I was using a portable CD player. We didn't have mp3 players yet. I had no clue about Bose. I probably figured that since it was $150 it might be good
I tried it again this year and it's still good, but I only paid $40. Despite what people say, it doesn't have bloated bass and severely recessed mids. Too much treble for me so I gave it away.
Want to know what's really funny? I think my next upgrade was an HD-580, but I was dumb back then and don't think I realized it needed an amp! No wonder I didn't like it.
I remember it being incredibly boring. Well, no wonder..
First REALLY expensive headphone was the K701 and I always loved it. This was back when NORMAL people (not head-fi people) considered any headphone over $50 stupid expensive.
I think my K701 was very under-amped, but still sounded good.
I later bought a DT-990 and remember one day being forced to part with one of them. Ended up being the DT-990.
My fun hit a wall when I bought a Grado SR-325i and hated every second of it. I'd probably like it now though. From then on I listened to only my Triple Fi 10 for 3 years and then finally got sick of it and switched back to headphones in late 2009 I believe.
I swear one of these days I'm going to stick with two headphones for good. Probably Q701 and DJ100. Who knows..DJ100 would be my "FUN" headphone for when I need a little extra bass.