I've had Sony MDR-7506s for about 7 years now, two cup replacements but otherwise going strong. I've also had my Audio Technica ATH-M50 for a solid 12 years, one cup replacement, sound great and work perfectly.

I have basically worn one of those two pairs of headphones every single day at work since I bought them; I guess I've just had good luck.

Which Sennheisers? Their 25 Euro in ears broke on me as well (C25x?), but as a pupil I couldn't afford better and just burned through some of those. Time lapse to a decade later, and I got myself the HD650. They sound exceptionally while still being relatively affordable (not that this would still be an issue, but I'm not a maniac who spends all their money on audio equip) AND they can take some abuse. At least that's what long time owners report, and that's also my own limited experience after 4 years - I take care not to trip over the cable and throw them across the room, but that's about all the care they get from me. [edit: okay, and if I stuff them in a bag, I'll stuff them on top or put some clothes between them].

Sounds a lot like the problem is between the keyboard and chair considering the absolute number of shit that you burn through in a couple of years.