Personally, it depends on what you wish to listen to. Personally, I would NOT go with the Dr. Dre Beats. It's true that the bass has a deep and satisfying sound to it, which makes it great for casual listening, especially to bass-intensive songs and genres. Drums 'n' Bass, Club, Techno, and Rap sound great with them. The noise cancellation works wonders, they're fairly portable, and they come packaged with several goodies.
The bass is also a problem though: The mids are mediocre and drowned out. Quiet acoustic pieces, orchestras, and ambience sounds unnatural, and even lacking. As a composer, I much prefer a natural flat-line sound... I enjoy listening to songs the way the mixer intended you to hear them. They REQUIRE batteries; It isn't optional. Their built quality is plastic, which is very worrying. My final complaint is the price: You can get professional headphones for $350.
I personally went with the Beyer Dynamic 990 DT Pro. Now, this is probably overkill for you. However, not only are they the most comfortable headphones I have had the pleasure to wear, they are PERFECTLY balanced. And they're the same price, $350 ($179 on eBay last I checked). Is that what you're looking for? Perhaps not. Again, it comes down to preference: A lot of people ENJOY bass-heavy speakers/headphones, even if they sound unnatural. Should you go with Beats? They sound very good, but I'm unconvinced they're worth $350. At that price, there should be nothing wrong with them, and their build quality and requirement for batteries kills it for me.
While I don't have as much of an understanding about audio equipment as an audiophile, I have an understanding of the equipment as a composer: That's why I went with a different pair, and I could not be more satisfied with what I choose. Whatever you go with, I wish the best experience with them. They will hopefully last you for years to come.