I will be using them for ..

music ( ipod ) - my old regular ipod ones use to fall out alot if i go running with them..
movies and music ( via laptop )
computers at uni for lecture recordings
and maybe even while playing ps3

not exactly good with this, so i dont know what I should look for when i buy them.
the store i went to only had these ones here

http://www.sennheiser.com/sennheiser/home_en.nsf/root/private_headphones

but those seem to break down into a huge variety.

Any help would be great.
thanks
Hey guys thanks for the answers thus far.

however if i visit any site such as skull candy etc

they break down into so many styles, i just get confused.

a little more detail would be awesome.