Hi. Back in the day, I had a pair of Sony MDR-CD180 headphones. I enjoyed them quite a bit. Not too much base, comfortable, not expensive, and open air, so I could hear what's happening around me. Those have since broken and I've not yet been satisfied with any replacements. I got a pair of Panasonic X900s, and they sound good, but they're not as comfortable and they're closed.
What I'd like is a pair of circumaural headphones (completely cover my ear, not resting on my ear at all), open-air (so I can hear my friends talking around me while I have my phones on, and for under $50.