I can assume from your other post that you are talking about headsets. First question: How much do you want to spend? Logitech is just one of the name brands out there, and you could get a better deal on something just as good. I got the Logitechs because they were the only USB headsets at the Winston-Salem Best Buy, and I needed USB because I already have the other jacks full on the soundcard on my computer.
I have to admit that I am really satisfied with mine. Plus, they are on sale for $45 at Best Buy now.
Also consider one of these:
http://www.plantronics.com/north_america/en_US/catalog/display_category_type.jhtml?id=cat1430032&rootId=cat640035&productTypeId=cat1430032
I use a Plantronics headset at work, and it is really good quality.