The main problem with the "Gamin Laptops" are that they are mainly overpriced...
Alienware and XPS cost alot more than a contemporary mainstream model, even from the same production company...
I would reccommend you take a look at ASUS N53 (link
http://usa.asus.com/Notebooks/Multimedia_Entertainment/N53Jf/#specifications)
Good processor, decent graphics... light weight. 15.6"
I am only usings this one as an example, since I don't how the price range for Laptops are in the rest of the world (Greenland being notoriously expensive).
If you can find this laptop on your preferred vendor, try and compare it with a ASUS G-series laptop of same specs...
I'm sure you can find a Dell, non-XPS with same spec as the other to a much lower price.
Just my two cents...