In the context of earbuds, probably the KSC75. I disagree when I'm comparing that to the 2019 NiceHCK MX500, but both are great value for money.
My Yincrow X6 is due early next week, so I'll be sure to compare to my KSC75X.
I've had the KSC75's (on parts express headband) for years, and they are definitely classics (although personally I prefer the portapro/sportapro drivers on parts express headband for a little more bass).
I've had the 2019 NiceHCK MX500's for a week, and they are definitely awesome as well! I'm really happy with how they sound.
So yes, both are awesome value for the money
Yincrow X6 are here, and they are shaping up to be excellent value as well.
Sans foams, bass is clean but lacks a little authority and the lower mids feel sucked out. Highs are clean and the lower treble and upper mids are balanced.
Donut foams fixes the bass and lower mids, but the contrast between the upper mids and the lower treble makes upper register vocals sound very hot to the point of piercing.
Full foams offers the best balance, at the expense of a tiny bit of mid detail.
Comparative to the MX500, the MX500 are great with donut foams while only touching the edge of sibilance via the same mechanisms, and are outright euphoric without foams if you're listening to something almost entirely devoid of anything below 100Hz. Full foams dampen the soundstage and bring the lower mids forward a bit more. As has been identified before, the X6 brings the bass, and eats into the detail level a touch with the highs and mids. Both are great, and both have their place, with the X6 being more versatile.
Compared to the KSC75s, the X6 offers better bass compared to the standard KSC75 fitment, and weaker treble extension. The X6 wins on bass clarity, but loses on mid clarity and treble clarity, but the KSC75s accomplish this with more sibilance and perhaps too much of a bite on vocals due to the presence/lower treble boosts. Pressing the KSC75 closer to represent a headband fit, the bass hump and lack of clarity becomes more apparent and the soundstage narrows a tad, but the mids and highs remain clear.
Frankly, all three are great, and you can't go wrong with any of them, but I would describe the two earbuds as being more fun for more genres of music. The KSC75 when it hits its stride though, you really can enjoy the tuning without caring about and blass bloat or detail issues: it's quite euphoric.
I think most people would enjoy swapping between the X6 and MX500, and that the two basically have the KSC75 covered at the same price, with the MX500 reaching further than the KSC75 in most of what its signature does minus a presence boost, and the Yincrow X6 beating it in the genres where the KSC75 tonality and technicalities fall behind.
