Any music reproduction you enjoy is a good "system". While the high end stuff can get absurdly pricey, I think you can actually get better sound for the $ (adjusted for inflation) today than you could in the 70's. From $100 headphones to half million dollar systems, its all fun.
Funny Koss Headphone story: My roommates in college in the 70's plugged them into the microphone jack instead of the headphone jack by mistake on my Pioneer 939 receiver & realized they were also a good microphone. The battle of the dorms escalated & my speakers got moved to the window facing the quad & regularly in the middle of the night, many kids got woken up to a variety of "greetings". The speakers would then quickly get put back into their normal place before the RA could track down what was happening. This went on for months.