As with any piece of gear, there are no "best" headphones, only what works best for you. One big reason why is everyone's head and pinnae (outer ears) have different shapes and sizes. So come sets of cans simply work better on a given head or pair of ears. Another reason is that different folks focus on sound in different ways, and the closer the ear is to the source, of course the more that's going to vary.
For example, there are people who can't stand closed-back headphones, and some who dislike open-back phones, and each of these has certain characteristic sounds. Same with over-the-ear and on-the-ear headphones. Then there is the whole issue of how the pads feel, and how well they seal against your head. And some people like listening at relatively high volume levels, others prefer it lower, and headphones generally vary by how good they sound at high or low volumes.
Then there is the whole issue of impedance; some have very low impedance specs so they can work with iPods, etc., and others have higher impedance specs because they're designed for working with other kinds of equipment. So you definitely want to know your amp's headphone jack impedance to match it for best performance.
Anyway, it's a very, very personal thing. I say this because I have outside talent come to my studio, and I offer several choices in cans to them so they feel comfortable while performing (and for your purpose, a set of decent studio phones probably makes a lot of sense). There are times that the talent listen to a few sets of cans and pick one, and it's always different for different people. Rarely do they pick the ones I'd pick.
I'd certainly look at Grado's entry into that price level, Beyer's DT-770 can often be found for just a little more, Sennheiser's HD 280 are good, lots of people like Sony's 7506, Shure SH440 have gotten good reviews, AKG K240 are sets of cans you see at most studios, etc. Good luck!
Edit: Forgot to mention Audio Technica ATH M-50. Very good cans.