In Best Buy, the first panel I went to had 3 < $150 Sennheisers, 1 Koss, and 1 Japanese name (I think) didn't recognize the brand.
I felt awkward enough there ignoring the SAs and trying every single headphone against my Monoprice, so I didn't take the time to write down the names, but I got a good feel for where the Monoprices were in comparison and also got a better scope of what a lot of headphones sounded like.
1st, the Sennheisers were a lot weaker than I expected, I played several genres out of my Iphone on them, and the Senns seemed very quiet. Their strong point was clarity, their sound was very crisp and specific.
2nd, The Japanese one (started with an A, I'll go back soon and find out). These had a very full and fun sound. They actually sounded the best of al the bunch, but I won't comment too much until I can go back and get the name.
The Koss sounded better than the Sennheisers but were muffled.
The next booth was the Sol Republic booth. They looked pretty cool, but I think some of the displays had technical issues and only 2-3 of them actually worked correctly. I remember them sounding pretty similar to Beats. They had a very fun sound with a lot of presence. The highest end model actually sounded worse than the 80 dollar model (v8). I would say that my Monoprice 8323s sounded most similar to the v8 by Sol Republic of anything I tried there.
Finally the Beats by Dre booth was last and they had an enormous display with a flat screen TV playing a recording of spliced clips jammed together from various pop culture artists. Overall the Beats line sounded very similar to my ears. Despite varying several hundred dollars in some cases they mostly had the same bass heavy sound. Overall I thought my Monoprice 8323 were in the same ballpark as them, but I think the Beats had a brighter sound to them. One thing I noticed is that watching the video at the display kind of skewed my perception of the sound, closing my eyes gave me a more neutral interpretation of the audio output.
All in all, I was pretty pleased with how my 8323s fared‚—my mids were on par with the best in the store. I definitely expected to be wowed more by the Sennheisers, but they seemed so quiet. Whenever I get the chance I'll go back and get all the model numbers and brand names and make this post more specific, but I really just wanted to share my first experience listening to a ton of different headphones. Probably the biggest surprise the v8 which sounded as good as the best Beats and even the most expensive of its own brand name. So I guess if you wanted that same sort of fun rap sound it would be a good choice at only $80. I'll probably go back later on and try the Sony/Bose booths which were occupied by families most of the time I was there.