I don't know honestly. I work in a cubicle area though, so open might disturb the people around me. I'm not a professional sound mixer either, I work on animated films. So I'd like to use it for that, but mostly just want a more dynamic experience with sound than ipod earbuds I've been for years.
You could look into the AKG K81DJ's. They run about $50, and sound really nice. They actually do a lot well, for that matter. They have probably the best isolation in the sub-$100 price range, they are built very well, and of course, they sound nice. They are a touch on the bassy side, but their sound signature lends itself well for long listening times, without getting fatiguing.
Normally I'd recommend the Sony MDR-V6's for this price range, but their prices have been skyrocketing lately, and if you look around for cheaper prices, you have a very good chance of finding fakes.
If you want to save yourself some money, the Koss KSC-75's, despite their price, are a strong competitor in the sub-$100 price range. They are open, so you'd have to keep volume down, but they are balanced and detailed enough for amateur sound production.