Get the Beats, I got them and love them, the Studios anyways. I also had the SOLO HDs and enjoyed them but I will say I felt everything in the Studios was better than the HDs, especially the bass.
Don't get the Audio Technica ATH-M50s, that's what nerdy a.ss retards who can't afford the Beats say. I HAVE the Audio Technica M50s and use them for computer use, they are NOT BETTER THAN THE BEATS STUDIOS. They lack any type of bass, they are very very flat, you will not experience your music unless you drop $50 on an equalizer and they have a long a.ss cable which makes them unportable. I also found them to be uncomfortable after awhile of wear, the Beats Studios are my absolute favorite pair of headphones and could wear them all day.
Proof I have the M50s & Beats so I can actually give a credible opinion and not talk out of my a.ss unlike broke M50 nerds who hate Beats
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Also I can't speak for the 50 cent SMS audio headphones or the Soul by Ludacris, but the reviews I've seen have always said that Soul by Ludacris was very good and usually ranked them above 50's SMS audio phones, so if Beats aren't your thing there's still options- but I firmly believe Beats are the best if you can score them for the right price.
I dj and produce (actually for a living not just a bedroom dj), so I'll just give my honest opinion. Here are some that I'd recommend, Beats Studios or Mixr, AT-M50's (these are what I use for spinning at clubs and as he said, they are flat, so I also use them for studio use when engineering songs because they give a very true sound unhyped sound and don't have that hi-fi sound that most of us like for our day to day listening), AiAiAi Tma-1, Sennheiser HD280PRO (comparable to the AT-M50s, i like the sound of these a little better, just started using these at my gigs, I can't wear these for extended periods though, maybe I just need to break them in, but they hurt the area around my ears after about 30min), Sol Republic Tracks (i really like these for listening to music on mobile devices, I use these when i workout, yea i'm one of those losers who wears bigger headphones at the gym instead of earbuds), and my FAVORITE as far as sound quality is concerned would have to be Bowers & Wilkins P5's, my first time listening through these i was like SHAT!, thats what music is supposed to sound like. But these all are headphones that I either own or have used frequently (one of my dj homeboys swapped me his aiaiai's a couple times because he wanted to test a pair of mine before buying them). But your best bet would be to go to an Apple store and Best buy, between those two stores, you'll be able to listen to pretty much any good headphones that are on the market. I don't think you can go wrong with any of the ones that we listed.