New headphone/headset

Because they're just better. The SR-60s have kicked every other set of sub-$100 cans I've listened to out of the water. They may not look all too hot, but the sound quality is a fucking revelation if you've never had a pair of decent headphones before. You really can't go wrong buying them, unless, of course, you'll be listening to them in an area where others could potentially be bothered by the sound they pump out. They're entirely open, so all sound going into your ears goes back out the other way. This also brings up the issue of people hearing things you'd rather them not (i.e. your Britney's Greatest Hits album). For personal, at-home use, though, they really are top notch.

With all that said, as an owner of both I'm inclined to lean toward the Sennheiser set. They seem to fit the OP's description much better than the Grados, and the drop in sound quality really isn't all that noticeable to the average listener. Plus, they're a bit cheaper, which seems to be rather important, if I'm judging the capital letters correctly.

Either one's a real winner, though, so don't sweat it. I'd recommend checking out HeadRoom if you really want more detailed information.

Jam it back in, in the dark.