Any more, its more of a decision on where you will buy future music from and what software you prefer. I dont care what audiophiles will say as each side will bash each other, for the general purpose, its hard to go wrong with any of them.
Itunes=Ipod, of course.
Other music stores=non ipod.
allofmp3.com or other non drm'd (legal) mp3 sites =any mp3 player
cds only = any mp3 player.
Personally, i would go with an ipod mini because i like the itunes store and software more.