Really good heaphones. It's been years since I bought them and I'm still amazed almost daily just how good music can sound. I'll admit that the cost upfront was not exactly cheap, but if you divide the price by the useful lifespan (my previous headphones lasted for 8 years) it becomes a no-brainer.
Studio mainstay of the last 30+ years. Comfy as hell. Accurate enough, if flattering. <$100. I have a 20 year old pair that got a few new sets of earpads but sound as good as day one.