Alienware 17 R4, Lenovo Ideapad Y910 or Gigabyte P6/P57? Which one should i get?

Alienware 17 R4, Lenovo Ideapad Y910 or Gigabyte P6/P57? Which one should i get?

Added (1). https://www.dell.com/...hs1&~ck=mn

Added (2). https://www3.lenovo.com/...30142534:s

Added (3). https://www.saveonlaptops.co.uk/P57W-V7-CF1-Gigabyte-P57W-V7-CF1_2102447.html

https://www.saveonlaptops.co.uk/P56XT-CF1-Gigabyte-P56XT-CF1_2156519.html

Please let me know which one i should get?