The HD 280s are hands down the best headphones I've heard. I'm no audiophile though, but I think that makes me the perfect person to review these. If you're used to $500+ soundsystems (for sound quality, not volume), you may be dissapointed in these, and I'd expect you to be willing to spend more for a better set. However, if you're like me, and have bought $20 headphones your whole life, do yourself a favor and buy these.
Yes, those crappy $20 headphones sound fine to you, maybe they don't go very loud, and perhaps you even notice that its a bit hard to tell direction precisely (when gaming?), but they work, they serve their purpose - getting sound to your ears. BUT, listen to the HD280s, and even if you thought all speakers are the same, you'll instantly notice a difference. The bass will be deeper, and midtones more clear. You'll be able to go louder and quieter then you ever could on the cheapo pairs.
They also provide decent insulation, allowing them to work well in louder environments. This could be seen as an asset or drawback. It tends to isolate you from your environment. It also means they get somewhat hot when worn for long periods and/or when its warm in the room.