When my neighbors saw me mowing my lawn and listening to my iPod, I usually get asked which version is the best. I have a feeling iPods are going to be popular Mother's Day and graduation gifts this year. Anyhow, I ask a few questions about how the device is going to be used and make a recommendation based on that. This is for my neighbors so I can get the yard done before dark.
(note: updated version at http://www.rjdudley.com/blog/Which+IPod+Is+Best+2005+Edition.aspx).
iPod Shuffle
This is the smallest iPod--roughly the size of a pack of gum--and comes in 512K (approx. 120 songs) and 1GB (approx. 240 songs) versions. It's miniscule size and small capacity make this version practical only for working out or short commutes, IMHO. Although 240 songs is enough for a full workday, and either model could store an audiobook or two, you won't have much variety from day to day, and the lack of a display makes choosing a specific song next to impossible. Rearranging the songs on your device every day or so to provide workday variety kind of defeats the purpose of having a large capacity player, and I think the love of the device will be greatly reduced having to do so. For a spinning class or even tae-bo session, this is the perfect model. This model is flash-memory based, so there are no moving parts to damage during a high impact workout.
iPod Mini
For an average music collection, this is the iPod to get. It's 2 in wide by 3.5 in tall, so it's very compact, and holds 4GB, or roughly 1000 songs. 1000 sings is far in excess of the playlist of any commercial radio station these days. Because it's so small, this player can easily be used for a low impact workout, and it's larger capacity makes it practical for all-day use at the office and longer commutes. This model has a display, so you can quickly navigate to the specific song, artist or playlist you want. A number of audiobooks can fit on here for plane trips or long commutes, and still have room for a day's worth of music. This player is hard drive based, so it's not a good idea to wear for high-impact workouts, since you could damage the drive platters.
20 GB iPod
If you have a large music collection, or love audiobooks, this is the model to get. This version holds approx. 5000 songs, so there's plenty of room for large CD collections and audio books. It's about the size of a deck of cards, so it could still be used while on a treadmill or a spinning class, but just a little large and heavy for other workouts. Currently, the 20GB is the only original iPod offered--for larger capacities, you'll need to get an iPod Photo. Although this is tagged as an “original“ iPod, it's actually a fourth generation (4G) iPod, which is the latest version. There are plenty of other capacities in older versions available which will work just as well as the current version, but I definately don't recommend a used one.
60 GB iPod Photo
The 60 GB version holds approx. 15,000 songs or 25,000 photos (or some combination) and is also available in a 30 GB model (approx. 7500 songs or 25,000 photos, or some combination), although there are still some other capacities of slightly older models available. The major difference is larger capacity and a color screen on which you can display photos. Yawn. If you have an absolutely gigantic audio collection, this is your model for capacity reasons only. However, if you take a lof of digital photos, you can connect this iPod directly to your camera, and download photos right onto the device. Very handy if you need a lot of storage when away from your computer. The tiny screen is very sharp, but you're still looking at photos on something the size of a matchbook. You can hook it up to a TV and show your vacation photos to your friends, but that's so last century--real men photoblog. There is a rumor of a video-compatible iPod with Tivo-like capabilities. If you want to watch stuff on your iPod, wait for that version. There is a very good chance that the 60 GB model has a larger hard drive than your computer, so you'll be unable to store your complete music or photo collection on your computer, which is where you need to put it in order to get the stuff onto your iPod. Even the 30 GB model probably exceeds the free space on your hard drive. Unless you absolutely need the photo capabilities or larger capacity, I think th 20 GB original (above) is your better option.
No matter what version you buy, I definately recommend a protective case of some sort. You're about to drop at least a couple hundred bucks, and you don't want butterfingers to destroy that purchase.