Well, basically, the shuffle allows you to "shuffle" your songs (randomize); it's a waste of time imo... especially at it's tiny size...
If I had to go with an ipod, i'd likely go with the nano, classic, or touch... The touch is like an iphone minus the phone... The nano and classic both do video as well.
Difference from classic and nano: the classic has an 80gb/160gb version, the nano's max size is like 4/8gb...
All compliments of my best friend
Wikipedia