I swear my daughter was born singing! I have never seen a child so interested in music. This led me to research MP3 players in search of the best one for a young child. I found the SanDisk Sansa Shaker. Again this is a product with limited advertising, I have even found them on clearance.
Now, I know that there are many MP3 players on the market that advertise they are for children, this one is different. It has its own built in speaker. It allows my kids to listen to it without ear buds or headphones. This is a big plus, head phones do not fit on my daughters head properly, and ear buds are painful and annoying for small children. There is also the bonus of not damaging their little ear drums by turning the volume up too high. It also comes with two headphone jacks, so that two children can listen together. I originally purchased the Sansa Shaker for my then barely 4yr old and 6yr old. Without a doubt the best for the money. This has got to be the most durable player out there! You change songs either by twisting the top or shaking the player, the same for volume control, you just twist the bottom. It has an SD card that can be upgraded for added memory and only uses one AAA battery.
It easily fits in the hands of a small child. We even bought one for my 2 1/2 year old niece, thats how easy it is to use. For kids this is the best! I believe this is also available for purchase directly from the SanDisk website. The newer model is a little more expensive, it sports a 1G card instead of the 512MB that I have.