I haven't used any of those headsets, but I own a Gamecon 780. For the price I paid it is a fairly comfortable headset and the sound isn't fantastic, but it's still very nice for $55 /w shipping. Plantronics is a company to consider IMO because they have been making headsets for the call center industry for many years, Everyone I played with could hear me very well on the mic, and people commented on the quality of voice in my MP sessions fairly often. No complaints!
I would think that between those three the G35 looks like the best bet. Virtual surround is a nice feature for shooters, but for the best sound reproduction 2.0 is ideal for headphones. What you want to make sure of is that the cups go over your ears completely. If they don't the pads can become uncomfortable after an hour or so. That to me is the primary thing to look for with a gaming headset if you're putting in long sessions.
I used to have the Sennheiser HD 595 for a very long time, which was quite excellent btw. But really needed one with a mic, so after lots of reading, I naturally crossed over to the PC 360. Out of the box, it wasn't impressive at all. But after some burn-in, these cans open up nicely. I'd say they are maybe 90% of what my HD 595's were and are well worth the money for the sound quality, features, and convenience of having a mic it provides. Just my two cents