I have a Creative Zen Vision M, and this is what I got from a random play all (excluding audio book tracks and really short tracks):

Gentle Giant - An Inmate's Lullaby
Anderson Bruford Wakeman & Howe (offshoot of Yes) - Close to the Edge
Frank Zappa - Theme from the Third Movement of Sinister Footwear
Return to Forever - Dayride
Ayreon - Ambeon: Cold Metal
The Beatles - Good Night
Frank Zappa - Call Any Vegetable
Jethro Tull - A Passion Play (Part 1)
The Beatles - Another Girl
Frank Zappa - Father O'Blivion
Pink Floyd - Young Lust
Led Zeppelin - The Rover
The Beatles - Little Me
Gentle Giant - Free Hand
Nobuo Uematsu - The Prelude (from FF 4 Celtic Moon)
Joni Mitchell - Carey
Frank Zappa – Amnerika Goes Home
Frank Zappa – DC Boogie
Ayreon – Computer Eyes
The Beatles – Norwegian Wood
Marillion – Lords of the Backstage
Ayreon – Sail Away to Avalon
Andrew Hill (me) – Loss is Temporary
The Black Mages – Hunter’s Chance
Pink Floyd – Waiting for the Worms

This makes me look like a big Beatles fan, but I'm not - the truth is I put their discography on my player to see why my father likes them so much. The rest is a relatively accurate crosssection of my listening taste, though not all of them are songs I would have chosen to represent my favourites.