i just bought an Inspiron E1705 from dell a few weeks ago, essentially when upgraded, its a XPS. all fully loaded, for 1500 after tax, shipping and everything (normally built would be 2400 or something rediculous). I think i have a 35% off coupon you can use, really saves you a lot. Check out slickdeals.net if you get a chance they have a buncha deals all the time in the forums, just search for dell. I would highly recommend that route. You probably cannot beat the price for what your getting.
all depends on how much your looking to spend.
oh, and i have had an alienware, was not happy with the customer support and im getting better performance with the dell now than i did before and im spending half the amount. your really only getting the name with them, my 2 cents.