Yeah, I know I'm in the minority, but I find the DT770's (I've used only the 600 ohm and 120 ohm versions, though) an excellent metal can. I like my metal to have bass.
But the usual recommendation of Grado's for metal doesn't apply here, methinks. I think Jack is onto something with the Sennheiser recommendation, that might be a better choice, it's just not something I'd recommend, as I don't like them.