What speakers should I get for my gaming computer?

I recently got into pc gaming, and I'm in the market for some speakers. I have limited desk space, so I'm not looking for a full-surround sound system or anything, but I don't want something tiny either.
Right now I have some crap dual speakers and subwoofer, which don't work too terribly well. I like the setup, but the quality is a bit sucky. The volume is fine, but it gets quite tinny higher up and the bass (which is very important too me), leaves a lot to be desired; I want to feel it in my chest.
I'm not really tech savvy when it comes to specs, but for reference I have a fairly new Alienware laptop which is running Windows 7.
Right now my price range is ~$150, but I'm open to suggestions.

Anonymous2013-11-14T18:26:45Z

If you are not setting up a multi speaker surround system, a pair of headphones would fit better. Bass heavy sets follow:

XB500 Sony $110: http://www.amazon.com/Sony-MDR-XB500-Diaphragm-Driver-Headphones/dp/B001RB24S2/ref=sr_1_2?s=electronics&ie=UTF8&qid=1347079175&sr=1-2&keywords=XB700

ATH M50: http://www.amazon.com/Audio-Technica-ATH-M50-Professional-Monitor-Headphones/dp/B000ULAP4U/ref=sr_1_1?ie=UTF8&qid=1384482235&sr=8-1&keywords=M50

DT770: http://www.amazon.com/Beyerdynamic-770-PRO-250-ohms/dp/B0006NL5SM/ref=sr_1_1?ie=UTF8&qid=1384482253&sr=8-1&keywords=Dt+770