Lenovo Z51 series is very good , and as I am using Lenovo Z51 70 ( 80K600VVIN) , I found it very good.
Specs:
1-It has 8 GB of RAM which is very good and fast.
2-It has Intel I7 processor which is the latest version.
3-It has 8GB of Graphic card which mostly supports all of the games.
Besides all this it has a mind blowing large screen which is veru good for playing games and watching movies.
And it also has JBL speakers which gives very good sound.
So! Must go for it.