depends what you want it for. If you want to call people get the iphone 5. If you want it just for games, apps and internet get the ipod touch 5th gen or 4th gen (both are pretty much the same) If you want an ipod touch, but you find the screen to small or a wider picture for videos and face time, get the ipad.
ipod touch and iphone 5 pretty much the same thing just the ipone 5 much more expensive and you can call people with it the ipad is just a bigger ipod depends on whether you want a small screen or a bigger one.
Comparing 3 different things. A media player, smartphone & tablet. In that case its a matter of which you think you would need the most & benefit the most of having.