I did a lot of research into smaller capacity mp3 players this past summer and ended up with a Sandisk Sansa e280 (8 GB). The Sansa e200 series players are similar to iPod nanos in size and storage capacity, but have more features and are cheaper (paid $100 less than an 8 GB nano). The Sansa e200 series have nearly identical specs as the nano, but they also include a digital FM tuner, you can record from FM radio, you can make voice recordings, and they are expandable by up to 4 GB (currently) using micro SD cards.
The one big plus iPods have over most other brands is the range and choice of accessories. You can find most of the same accessories for other brands (including Sansa’s), but the shear volume of manufacturers and choices for iPod accessories is overwhelming. Having that much competition in the iPod accessories market is a good thing for the consumer IMO.
I you are looking to load all of your albums on to one player, then you'll need a higher storage capacity model. Ipod and Zune are the main choices in this regard with up to 80GB storage capacities. Keep in mind high capacity players such as this use mechanical hard disk drives that are more prone to failure compared to smaller capacity players in the 1 to 16GB capacity. Smaller capacity players typically use flash or solid state memory that is less prone to wear and failure over the long haul.
Whatever you choose to buy steer clear of players that are packaged with online music service providers as this may result in limitations to what formats you can load onto your device. As others have stated, always download or rip CDs in MP3 format and you shouldn't run into any problems.
