This group gives you the largest capacity for songs in the largest physical size. We are not talking a couple of hours of casual listening, but storing whole music collections (and other data such as calendar and address book). Apple's iPod, Rio's Karma and the H120 from iRiver are all hard drive players.
The iPod is definitely the leader of the pack, with 20 GB all the way up to 60 GB capability with the iPod Photo. The basic 20 gig iPod ($300) works with both the MacIntosh and Windows computers. Size-wise, think deck of cards. If you like the selections on iTunes, you will need to purchase the iPod as the music is sold in their proprietary file format. Also, it will not play the popular WMA file format, found at WalMart's and Napster's online music stores. Jack up the price to $400 and get the 40 GB iPod with a carrying case, remote and a handy dandy docking station negating the inconvenience of plugging or unplugging the player to your computer. Just place it in the station and you are ready for downloads. Another plus to the iPod...findability. While other players organize songs by file name, the iPod goes for artist, album and song style, a much easier song retrieval system. In fact, most give the iPod high marks in menu and user interface as well. What may seem minor now, can become a large pain in the neck when you are actually using the player. Another consideration is the power behind the player. You can't replace the battery in the iPod yourself, and will have to pay around $100 for a new one. The batteries can now hold a charge for 12 hours, which is great for those long trips away from home.
iRiver's 20 GB H120, which sells for $300, plays back all kinds of file formats including WAV, WMA, ASF as well as the MP3 and sticks in an FM tuner, a remote, and recording capabilities (requiring expensive add-ons in the iPod). But with added features comes usability, and reviewers note the H120 has a higher learning curve. If you are not one who enjoys taking out the manual for the full range of player capabilities, be wary. Take it up a notch with the 40 GB H140 ($400) if you think you'll run out of space. But sound quality either playing or recording is noted as the best in PC Magazine's reviews.
Dell Digital Jukebox (DJ) comes in 20 and 30GB versions and is just a tad larger than the iPod with a generous LCD face. Its sound quality and 16 hour battery are two more pluses for a solid MP3 entry. Although it is not as beefed up with features as the H120, and you need to use MusicMatch transfer software instead of user friendly drag and drop, it's a great value for $299.
Rio's Karma, a 20 GB player, is a compact option for those with a more limited budget costing around $250. It has the file compatibility of the H120 and responds quickly plus includes an Ethernet port. The downsides include fewer features, including no recording capabilities, and its comparatively chunky size.