*sigh* another "best headset" thread. Do a search and you'll clearly see that the PC150 is probably the most highly recommended headset here (audiophiles, please note I said headset and not headphones). BTW, I LOVE mine. Here's my review from newegg:
Pros:
-Best headset/headphones/earphones I have ever owned
-Crystal clear sound at all levels
-Awesome bass, very clear and loud
-Very clear sounding mic
-Very comfortable, even if worn for 5 hours straight
-Fits securely on my head, won't fall off
-Good mic placement, away from face so there are no breathings sounds
Cons (I'm nitpicking):
-Most expensive headset/headphones/earphones I have ever owned
-Maximum volume is not loud as I would like it, although I would never listen to it that loud.
-Heavier than most cheaper headsets
-Foam is a bit hard
Overall, this was a great buy and I am very satisfied with this item.
Also, please note that Sennheiser is planning to release the PC160 soon which was specifically designed for gamers, especially ones who go to LANs a lot.