I can't make a personal recommendation... I've never listened to the headphones you mentioned.* The HD555s have a good reputation. Some AKGs have good reputations too, but I'm not sure which models.
You should probably go to a store and
listen to some headphones. They might even let you plug the display model into your iPod, which would be good because you can find out how it's going to sound with your iPod and your program material. (It's hard to tell what headphones/speakers really sound like if the store is playing music that you don't usually listen to.)
QUOTE
Someone also told AKG K271s are good for rock but I've heard alot of bad reviews about them for mp3 players.
I would want to know
why they are "bad for MP3 players"... The only thing I can think of is that they may have low sensitivity, and that you drive the player into distortion when listening loud.
You might get some good advice here, but look for some reviews (maybe check-out
GoodCans.com) and then go
listen before you make a final decision.
*I have a pair of Sennheiser HD280s and a pair of
Grado SR225 headphones which also have good reputations. I prefer the sound of the Grado headphones, but they are not sealed like the HD280s, and sometimes I need sealed headphones.