Ipod is out of the question: no features, high price.
Gmini: very beautiful display, video(divx, xvid) 30fps, playforsure(402), tv-out (display contents on tv), avg. battery. (i think it is fine for me because it lasts during the day and i charge it during the night) cf card slot/usb host
X5: i don't know much about. screen is not as big as gmini, only plays video at ?15fps, longer battery life than gmini.
it really depends on what you want more. longer battery life, or bigger screen, better video quality.
I chose gmini400.
which one should i buy based on overall features???