The thing to remember though is that these products are post introduction of iPod. If it wasn't for the iPod the competition wouldn't have had to up their game, in fact they wouldn't even be in the market.
But yeah, there are better MP3 players, depending on what you want. For simple stuff like just listening to music, the Sansas are great.
But each new iPod, each new generation, gets means the competition have to go back to the drawing board.
The other things often mention like DRM and restrictions in files. Well it's an Apple product, so they want you to get the Macs to run it better and with no fuss. But it took the iPod and DRM to legitimise the legal music download market. That's why big retailers push the iPod over others, but without the issue of DRM on iTunes, the only way to get music digitally would be like it used to be: illegally.