It would help to know a little more about what they are going to be used for (ie what genres of music, amped or not, preference of sound signature etc). For gaming I would recommend open back headphones over closed for the wider soundstage, unless you plan on using them portably (sound leak and no isolation). I also like being able to hear things around me and how loud my voice is but that just comes down to preference.
I listen to a lot of rock and prefer bright headphones so I bought a pair of grado sr80s when I was in your situation. Grados definitely aren't for everybody though and I wouldn't recommend them to you with so little information.