I bought some QC25s when I moved to a big open office. For me, they don't help -- what they do is they kill all the background noise, but then the individual voices still come through and they come through as the only thing I hear.
I could play music, but sometimes I like the roar of silence.
I'd like to buy a nice pair of headphones but that's the thing that worries me. I'm not at all bothered by the background noise (e.g. aircraft engines) but human-made noises are very distracting. There seems to be nothing that can filter them out; my current passive headphones will muffle conversation a bit when I've got white noise playing through them but throat-clearing cuts right through.
I could play music, but sometimes I like the roar of silence.