The best bang for the buck would actually be
This GT60 Dominator. It would leave room in the budget for a
Good SSD and
cooling pad.
That would give you the absolute best performance and experience for your budget.
Let me break down the list a little more.
Samsung Series 7: Last generation processor and a 2 generation old graphics card. Way overpriced, no idea why its on the list.
Alienware 17: Last gen graphics that are nowhere near as fast as any others on the list except for the Samsung, yet it remains an overpriced $1500 laptop. Alienware is awful.
Fangbook Evo HX7: Very unreliable brand. Avoid these.
GE70 Apache Pro: Could easily get a GT60 for this price and the GE series is a lower quality and less feature filled version of the GT series.
Toshiba Qosmio X-70: Again, a low quality brand that will lead to a poor experience. Not to mention it's really expensive for a machine with a 770M in it.
Valkyrie C7-27: ibuypower is a pretty bad brand. Avoid them. if you look up their reviews you will find a lot of unhappy customers.
MSI GT60: While this is the best option, the model with a slightly lesser CPU is $100 cheaper and you will not notice the difference.