The Shure SRH840 and the Audio-Technica ATH-M50 are both about $150 on amazon... which one is better for an all around listener?
The problem with the M50s is that the bass is bloated and it downs out the mids and the highs are not that great either. The SRH840s would be the much better all around listeners choice. If you mostly listened to Rap, R&B, and dubstep then I would say the M50s would probably be the better choice.
i personally found then fun to listen to once in a while but I ended up selling then because I enjoy the other ends of the spectrum.
personally i find the M50 to have quite good and deep bass, the treble is also quite clear mids recessed, the SRH840 has more natural sound, even better detail and a better soundstage i feel, just the bass is quite lacking in terms of extention and impact.
Out of the two I prefer the SRH-840 by a long mile. They are a lot more balanced sounding than the ATH-M50, and sound more refined. They are warmer and smoother, but that is a good thing to me. I like the neutral-ish signature of the ATH-M50, but it's pretty V shaped with not much magic in the mids. The SRH-840 is a lot more satisfying to me, even with it having less bass. Bass isn't everything and is overrated.
Without an amplifier the 840's would definitely be the right decision. with an amplifier comes the decision if you want fun, colored headphones or neutral, true sounding phones. if you're looking for neutral, the 840's are for you