i like my sansa e series because it's fairly small yet handle-able,,,but it's clumsy when i want to change directories.
i like my sony 728 and 729. great great screen, easy navigation, awesome battery life, really nice looking, common sense placement of the earjack at the bottom(since i always place my player upside down in my pocket). very intuitive.
cowons are ugly but they have great sound and their buttons are similar to the iriver t series.
i tend to use the iriver t10 the most because i use it all the time at the gym. for gym use, i think the t10 is the best there is. improved lock switch. but mainly it's the clip at one end that allows you to clip the player onto anything anywhere,,,while other people hold their players or use that ugly arm strap, i can clip the t10 anywhere including the waist band of my shorts(which is the most common sense place to put it)
btw,,,,i am totally anti-apple