Which Laptops you preferred i don't know anything about them. But i will suggest that you prefer to buy a Dell laptop because dell have a good quality and you also want to play games on the laptop that's why Dell is very suitable for you. I am also using Dell inspiron 1545 from last 2 years everything is best in it i'm also use to play games. i have never face any problem with it's battery backup is also good.
Don't buy the HP Pavilion there are major problem with the motherboard - tbh just go into a computer store and look around see which ones you like, my final decision was made on how pretty it looks , also look at the weight of each laptop
+1 for the Sony Vaio.
I have a core 2 duo that has been trouble free for the last 3 years.
I just recently replaced it with an i7 G73 Asus, but the Sony still works fine.
I suggest you Lenovo Y460N.Since Lenovo purchased the IBM PC department,the Lenovo's laptops have improved a lot.Heat dissipation or other technics are advanced.
As far as i am concerned, i would go to lenovo series,because its solidly built and look stylish and the major advantage while comparing it with others is, it doesnt gets heater even if you work continues for 24hours,i use lenovo g550 series its well polished and has a decent graphics where i could play top games which require graphics card. dont chose hp it gets heater even if you work on excel and it boils if you play games.
The Asus G73 is a great gamer if gaming is important. You can get the single 600gb HD, ATI Mobility Radeon 5870, and a core i7 Q740 for just a tad over $1k.
Another plus is that there is a second drive bay, so if you wanted to add a SSD to
your system for your OS and games it's a simple plug and play.
That would give you a WEI of 7.2 which is pretty snazzy for a laptop.