Koss KSC75, period. (The original, not the X.)
And some distance below that you can start talking about things like Superlux HD668B, HD662 Evo, HD681 Evo, PortaPro, M40x and a few others on here. (And stop it with the bad jokes of including Bose and Beats and even Sony on such a list.)
Bose and and beats as bang for a buck xD. They would be quite the opposite in my book. If you really want bang for your buck, get a second hand dt990, hd650/hd6xx, ath-m50
And the shp9500 is decent if you want a super cheap product... but sound quality/$$$ wise, i would always go for a higher class and second hand product.
Which is also better for the environment btw ;)
they're actually not as bad as they seem. Definitely better than beats, but not as good as the ATH-M50, for example.
Are they a true audiophile-grade headphone? no.
Are they better than standard-basshead-crap-earphones? you betcha.