Hi there.
i use two of the cans in your list, the SONY and AKGs. Cans are alot like moniotors in the sense that what one person finds appealing, another gags on it...that being said;
I prefer using the AKGs. i like the sound which can be described as pretty flat, and they are VERY COMFY... sorry, for the caps, but i think thats an important point, esp if youre gonna be using em hours on end. Some cans, like certain Fostex models, are pretty decent when you hear em, but after 20 mins, you feel like your ears have been crushed....coz they basically are, with two cones slapped on em, pumping loud music. The 240s remains comfy for extended periods, and that is a pretty important consideration IMHO.
soundwise, i find the AKGs very flat, whereas the SONYs tend to sound a bit more 'hyped'..sounds like you've activated somesorta 'bass/treble boost' switch or something. thats not a bad thing, in fact thats one of the reasons why the SONYs are so popular.
be aware thou, these cans appreciate a good amp driving them, esp the AKGs. try plugging your AKGs into your soundcard's headphone outs, and you'll find that they are VERY difficult to drive, never getting loud enuff. the SONYs are apprently a little easier to drive, so you might want to check on that.
best bet, try all three with some familar music and see which one you like.
Happy shopping!