I was using the logitech chat headset that came with guildwars no probs.
Have recently bought a pair of speedlink medusas and am very happy with them.
Theyre a lot comfier than the logitech ones, sound also seems a lot nicer, according to people on vent and ts the mic is also a lot better too.
However as it doesnt say on the specs on OcUK I'll add,
There is no longer a cd/dvd switch
And the headphones amp requires a wall socket too.
And you may need a forklift truck to carry the box coz its absolutely huge !
EDIT:
Also see this thread:
http://forums.overclockers.co.uk/showthread.php?p=6365342#post6365342