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