another vote for the 580's; combined with good headphone amp, these are great for music and gaming.
Here's a more indepth report on the cans.
And for anyone interested in more info on
headphone amps here's more.
As was pointed out earlier, with the impediance of these cans you'll either need a strong sound card or headphone amp. I have one of the portable amps and constantly fighting my kids and wife for it, when they use their portable players. If you're a serious headphone user I think you'll notice and appreciate the difference that a headphone amp makes.