The Meze 99 Neo is one of my faves at this price point. Arguably, one of the most comfortable headphones, ever ( I am not exaggerating). They have a fun sound with pretty good bass response, they're closed back, and can be driven from a cellphone or PC without the need for an amp (easy to drive and low impedance). They're $200, come with a hard travel case, and can be used portably just fine.
While I like the 58X, they are not the best for gaming and they are not the easiest to drive. They are 150 ohm drivers, after all. Same with the 6XX. You'd spend more on proper amplification to get them to sound their best and they're also not the best with Hip Hop or gaming IMO.
If you can spend a bit more, the HiFiMan HE4XX is a solid bet. I used them quite a bit playing Titanfall, Battlefield, Wolfenstein, etc. and enjoyed them VERY much. They have really nice sub-bass as they extend to 30 hz and they are very clean sounding. Foot steps and other ambient noises will jump out at you while gaming due to their imaging and soundstage. The only issue is they like power. The more power the better. As long as you can meet that requirement, I don't think you'd find a better starting set for gaming and rap. Even something like the 02 amp or Atom would be enough to comfortably push the 4XX and give you a big upgrade for little money.