Which Gaming Laptop should I buy?

Hi!

I'm going to buy a new gaming laptop soon and my budget is around $1500. I need help deciding which to buy in terms of specs, build quality, and how future-proof it is. I prefer to have a 15.6 inch but I may buy a 17.3 if completely necessary. So far I have narrowed it down to these three options:

MSi GT60 (Nvidia GTX 770m) - http://www.ncix.ca/products/?sku=84160&vpn=9S7-16F411-003&manufacture=MSI&promoid=1035

Asus G750JW (More expensive than other two laptops) (Nvidia GTX 765m) - http://www.amazon.ca/G750JW-DB71-CA-17-3-Inch-Notebook-Processor-Windows/dp/B00DHPP35M

Alienware 17 (The one priced at $1499) (Nvidia GTX 765m) - http://www.dell.com/ca/p/alienware-17/fs

Which is the best overall for build quality,specs, and upgradability, and just the best overall laptop? Please help me.

Also, if you have any other recommendations for gaming laptops that would be better than these ones and are around the $1500 dollar price range that is available in Canada, please comment on that as well. 

Thanks!

The msi with the 770m