Check out the new Alienware m14x 14-inch gaming laptop replacing the M15x. The M14x as it has the newer 2nd gen processors and overall more performance for the buck. Dell may do occasional sales to unload remaining inventory on the M15x, but it looks unlikely due to the replacing models currently available.

For those that didnt know, the M15x was a 15-inch model in the long line of Alienwares gaming laptop, usually coming with a hefty pricetag, but in return you get a powerhouse machine with mid-to-high end CPUs and GPUs.  The M15x came with choices of i5 and i7 options, along with standard Radeon HD 5730 GPU.  While the GPU was certainly a fast-mid range option that can run many modern games without issue, you can get similar performance from other manufactures such as Lenovo with a much cheaper price tag.  

If you're still interested in a 15-inch or so gaming rig, the m14x linked above can be a good choice, but a nice direct comparison to the 15-inch Alienware would be Lenovo's 15-inch IdeaPad Y570, which is currently sporting some serious hardware in the form of 2nd gen i5/i7 Sandy Bridge processors along with a very heavy duty GeForce GT 555M.  We highly recommend you to check this system out as it'll definitely give you some bang for your buck.