There are many models there. What games you wanna play with ? If you are super gamer, I would recommand you to take ASUS G50Vt-X5 or ASUS G51VX-RX05. If you are not , you may pick one from HP or MSI ...
Will it be safe to buy refurbished "ASUS G50Vt-X5".
It's under $750!
And has only 3 months of warranty!