i agree on desktops still be the best way to go for getting your money worth, but if you buying a laptop and you intend to play games, then just make sure you dont by stuff like toshiba, hp, fujitusiemens, and so on, go for the gigabyte, lg, or dells, you wont be able to upgrade, that is just the downside of laptops, and their hard drives tend to fail more than desktops, i guess you can say that buying a laptop in my experiance is like buying a car, its just a running expense.
any way, alienware i have looked at before, and its not really all that, i do think that it is just over priced.
point being, if you dont really have money to waste, get a desktop, if money doesnt really matter, get yourself a laptop but make sure you have a external one with all your data backed up to.