Which of these laptops should I buy for gaming?

Ive been looking at the [url=http://www.laptopspark.com]Alienware M11X and the Acer Aspire TimelineX 3820TZ, but im not sure which is best for gaming.

I currently have a terrible Dell inspiron.

The games I would like would be Fallout games, Dead space, Amnesia, games like that, so pretty much very high spec games.

Here are the details:

Acer

P613G32nks

Intel? Pentium? P6100 Dual Core Processor

13.3" HD Screen

Windows 7 Home Premium Edition 64-bit

3GB RAM

320GB HDD

Integrated Graphics

Up To 8 Hour Battery Life

LX.R2Z02.011

Alienware M11x

1GB NVIDIA? 335M graphics

Less than 4.5 lbs and has over seven hours of battery life with NVIDIA Optimus? graphics switching technology

double data rate 3 (DDR3) memory3, engineered to support the powerful next-generation processors that are designed to bring you faster speeds and higher bandwidths.

Acer TravelMate TM5742-7159 Notebook Intel Core i3 380M(2.53GHz) 15.6" 2GB Memory DDR3 1066 250GB HDD

ACER laptop