gaming headset better than speakers?

A good stereo headset is capable of emulating surround 7.1 (and in my opinion sounds better than a real 7.1 headset as the drivers are biggers, produce more bass and anyway you only have 2 ears so the emulation of the soundcard produce a really positional audio, you can hear what is coming from behind, side, on top or below you, it's really good...)

Note that the 1500 and the 2000 are both Stereo headset that emulates 7.1 and like i said it'll be better in my opinion than any 7.1 (4 speakers per ears) solutions... The actual differences between the 1500 and the 2000 are mostly style and wireless (the 1500 isn't wireless)

I use a headset and a 5.1 speaker system, it's about the same, only noticeable difference being Vertical sound difference when using a headset (When someone walk on the floor below or up to you, it lacks a little on speakers as speakers aren't below or upside you and can't change place alone...) it only depends if you like more gaming with an headset or wihtout one...
(i use steel series siberia V2 with an amplified Xonar soundcard and logitech Z-906 speakers)

I tried many headset and for gaming (and for less than 100$) i think the siberia is one of te best if it's not the best (however Corsair wasn't producing any headset at this time)

As far as music and movies, the speakers are better in my opinion... it all depend on your specific experience...

PS: If you have a sound card (other than integrated chipset audio) i suggest that you pick a analog connection headset over a USB one... However if you use integrated, pick an USB one as the USB soundcard will be better than any onboard audio...

Also i can recommend you to try any headset before you buy it if possible (somes are larger, taller, more comfortable, you'll like more bass or more clarity, each have their specific sound and comfort...)

I agree with what spawnkiller said.

I use audiophile headphones for gaming too, and it sounds much better than crap like the Tiamat(never buy this) with 4 drivers in each ear for surround. I have an easier time with positional audio with good headphones with virtual surround than those gimmicky true surround headphones.

If you buy a set audiophile cans too, you will need to get a sound card.

Speaker systems are nice for gaming, but a lot of factors in room configuration come into play for surround.

If you're playing first person shooters online I would say always use headphones.

Between the Corsair headphones, it will depend on if you want to spend the extra for wireless headphones. 1500 looks like the best option unless you want wireless(2000).