I'm personally a fan of Skullcandy especially because the style and range of colors for the cans are awesome but I probably won't buy another set of GI headphones... I've gone through two sets now. Both of mine have lasted a year and a half each and the same thing has happened. The plastic for the adjuster bar is quite thin and has a tendency to crack and break. It's a shame too since I love the style and these were very comfortable. The sound is decent for their size.
I wouldn't recommend these to anyone but if you must get them, I recommend that treat them gently. I was rough with my first pair, hitting the slopes and wearing them all the time. I only used the second pair in my dorm and they still broke after the same amount of time. Note, they have less chance of breaking if you don't pull out the adjustment at all but that's determined by your head size.
Pros: Decent sound. Built-in volume adjustment. Sweet extras. Skullcandy look/style.
Cons: Durability. Very weak construction...plastic tends to break around adjuster.
On the Hesh: Basically same headphones but with more powerful drivers. Same durability issues.
I've tried most of Skullcandy's products so hit me up if you have any questions.