Creative - My mates got a zen sleek and its a lovely bit of kit, very easy to use and very nice sound quality. I love the search feature in it meaning you dont need to scroll down a load of artists get get what you want and i also liek the fact that you can set your own theme and wallpapers on it. Only problem is that my mates has just started to develop dust behind the screen, and Creative wont replace i tunder warranty and he doesnt want to pull it to bits to clean the screen.
Sony - Very nice players, but i really dont liek the software required to transfer the music, but i aint used SonicStage for a while so maybe someone else can comment. The software alone made me ditch my minidisk as it decided to not install at all, and when i got it installed it wouldnt open, which made my minidisk a £100 brick.
Apple - Good value player, but be prepared for it scratching. I know 3 peopel with these players and all of them are very badly scratched on the screen even when using the protective leather casing. However, it is the cheapest, and it is easy to use.
Another one i would look at, and its the one i want when i can afford a replacement is the Cowon iAudio X5, maybe check that out before deciding as its a littl emore expensive than the ipod, but its gets much better user ratings.