Some of the Best and Most Popular Digital Music Players.
Note: This list is for devices which who's primary function is to play music. Other devices, e.g. Mobil phones and PDA (Personal Digital Assistants) e.g. Palm are also comming equiped to play music, but usually with lower capacity memory.

HARD DRIVE (20-60 GB) PLAYERS
Model	Capa- city	Format	Features *	Cost	Rating Cnet/PC Mag
Apple iPod	60G	MP3, AAC, WAV, AIFF	FS, PIM	$335-419	8.3/4.5
Apple iPod Photo	20-60G	MP3, AAC, WAV, AIFF, Audible, JPEG	FS, PIM, 2" 220x176 color LCD	$400-450	4.0
Apple iPod U2	20G	MP3, AAC, WAV, AIFF, Audible, JPEG	FS, PIM	$329	4.0
Sony Network Walkman NW-HD3	20G	MP3, ATRAC3	FS	$250-300	7.7/
iRiver H320	40G	ASF, JPEG, MP3, Ogg Vorbis, WMA	VR, FM, and photo viewing, 2" color LCD	$340	4
Rio Karma	20G	MP3, WMA, WAV, Ogg Vorbis, FLAC		$200	7.0/4
PORTABLE VIDEO PLAYERS (PVP)
Archos Gmini 400	20G	MP3, WAV, WMA, MPEG4-SP AVI	FS, VR, LI, photo/video viewer, AV Out, FS, 2.2" 320x240 color LCD, CompactFlash™ reader	$270-430	8.0/4.5
Archos AV420 Pocket Video	20G	MP3, WMA, JPG, or BMP, MPEG4-SP AVI	VR, AV recorder, photo viewer, FS	$400-615	/3.5
Archos PMA430 Pocket Video	30G	MP3, WAV, WMA, JPEG, MPEG4-SP AVI	VR, LI, AV recorder, photo viewer, FS, PDA, WI-Fi, Opera browser, USB Host port, IrDA port, Linux OS, 3.6-inch/ 320x240 pixel screen	$630-720	/4.5
Archos AV700 Mobil DVR	100G	MP3, WMA, JPG, or BMP, MPEG4-SP, DivX, AVI, WMV	VR, AV recorder, photo viewer, FS, 480x234 LCD	$800
MICRODRIVE (4 TO 6 GB) PLAYERS
Apple iPod Mini	6G	MP3, AAC, WAV, AIFF, Audible	FS, PIM, 8 hr. battery	$180-200	8.0/4.5
Rio Carbon Pearl	5G	MP3, WMA, Audible	VR, LI, FS, 20 hr battery	175-220	8.0/4.5
Creative Zen Micro	5G	MP3, WAV, WMA	VR, FM, FS, PIM syncs with Outlook, 160x104 LCD, 12 hr battery	$180-230	8.0/4.5   †
Gateway MP3 Photo Jukebox	6G	MP3, WAV, WMA, JPEG	128x128 Color LCD (can't pan or zoom)	$250	/4.5
Dell Pocket DJ	5G	MP3,	1.6" LCD, 10 hr. battery	$149	/4
iRiver H10	5G	MP3, WAV, WMA and AA, JPEG	VR, FM, picture viewer, 1.5" 128x128 LCD	$190-270	/4
Palm One LifeDrive	4G	MP3,	PIM, photo viewer, Wi-FI, Bluetooth, 3.7" 320x480 LCD	$500
FLASH-MEMORY PLAYERS (256 MB - 1G)
iRiver iFP-799	1G	MP3, WMA, OGG, ASF	FS, LCD	$190	7.7/4
Creative Labs MuVo TX FM	512 M	MP3, WMA	FS, FM, VR, LCD doesn't list tracks	$115	8/4
Samsung Yepp YP-T5 V	256 M	MP3, WAV, WMA	FS, FM, VR, LCD	$80-150	/4.5
Apple iPod Shuffle	1G	MP3, AAC, WAV, Audible	FS	$129	6.7/4

  † one of Bill Machrone's (see below) favorites.

* Terms:
FS - file store - Acts as an external hard disk to store files from your PC
VR - Voice Recording
FM - FM Radio
LI - Recording Line In
ID3 tag a 128 byte at the end of MP3 audio tracks identifying the title, album, ... IrDA - Infrared
PIM - Personal Information Manager (e.g. address book/contacts, calendar)
USB Host - Acts like a computer; you can plug in a USB keyboard, camera and download pictures, etc.

Summary:
Small Hard Disk (5-6G) players:
The Apple iPod has the best user interface, although a few people don't like the navigation wheel. It is the most popular and has a large after market selection of add-ons (speakers, cases, ...)
The Creative Zen Micro has more features and better sound than the others but a more difficult user interface.
The Rio Carbon Pearl has more features and better sound than the iPod and looks slicker than the Creative Zen Micro.

File Transfer With

Model	Napst	iTun	Real	Music Match	WMP	Win Amp
iPod mini		X	X		X	X
Zen Micro	X			X	X
RIO Carbon				X	X	X

WMP - Windows Media Player

Music Downloads Compatibility:

Model	Napst	iTun	Real	Music Match	Audible
iPod mini		X	X		X
Zen Micro	X		X	X
RIO Carbon	X		X	X	X

Download Services (legal)
Early Peer-to-Peer (P2P) services like the original version of Napster and Kazaa, Morpheus, iMesh, Grokster, and Blubster got in trouble with the music industry for violating copyrights. Since then legal services selling songs for about $1/song have emerged.

Service	Tracks	Bitrate	Format	Rating
Napster	1M+	128	WMA	4
iTunes	1.5M+	128	AAC	4
RealOne Rhapsody	1M+	160	WMA	3.5
Yahoo	1M +	192	WMA	4
MusicMatch	800K+	160	WMA	3
RealPlayer	700K+	192	RAX	4
Audible	18K (books, ...)	32	AA	4.5
Wal-Mart	500K +	128	WMA	2.5

See:
Music Services at mp3.com
PC Magazine: Music Download, Music Sites, services
Music Genre
Digital Music Services
Guide to Internet Music Services at montevallo.edu
forbes.com/markets/2005

Bass performance or Players:
Most digital audio players have weak bass performance because of the limited power in their amplifiers and the more power required for bass.
Some "in-canal" ear phones lower the impedance to increase sensitivity, but this futher loads the amplifier and reduces the bass response.

A headphone amplifier will fix this. Commercial versions run about $250, but you can get a variety of good homemade amplifiers on eBay based on the Chu Moy (cMoy) design for about $50 ($75 for the xMoy 2 amp version). (They may come with an Altoids can case, but they work.)
See articles at: DansData.com

See Bill Machrone's article at his SpA site.
Pocket Headphone Amp at fixup.net.

See Also:
Audio Formats in Audio-Video under technology
MP3 in technology
MP3 Player Reviews at cNet
MP3 and Digital Music player Reviews at PC Magazine
Bill Machrone's SpA: Serious Personal Audio (Bill is a PC Magazine reviwer)
Top 10 players at SpinFree News
ConsumerResearch.com
Top Players at at mp3.com
Consumer Reports Magazine