will this run the following games?

You are getting screwed. You’re close to having the perfect configuration, but for some reason that sales rep set you up with outdated specs. It is not a huge difference in price either, so I don’t know why they did this to you. I just ordered mine a week ago, so I’ll tell you the ideal specs you want. *If you’re a student you get a 10% discount from dell so you may want to ask about that* ***Most Important: Change the Processor, RAM memory, and Graphics card, You’re being sold outdated parts (Yes it can play Assassin’s Creed 2, but it would struggle with Mass Effect and games like Crysis) These are the 3 most important specs for gaming and have a huge impact on performance***

Processor should be the : i7-740QM (same exact price, but better, they just added that and you need it for the faster ram, the I7-620QM is outdated)

Memory Ram: 4GB@1333 MHz it’s better than the 1066 and only available with the i7-740 and higher

Graphics card: You want the GTX 260m it’s the best graphics card that is offered in the M15x and the single most important thing for gaming. It’s only $ 50 more and outperforms ATI. The GTX is currently in the extreme gaming category and the ATI falls just short of that, if you’re just ordering a computer, let alone an alienware, don’t put an outdated card in it to save $ 50, get the GTX 260m

wirless card: not a huge deal but the one you have in it only works with n modems and the intel for $ 49 is compatible with A & G & N modems. Which just means you have a higher chance of connecting wherever you go. If you’re plugged directly in most of the time then it doesnt matter, but it’s nice to have just in case.

Screen: if you want true HD gaming and have $ 100 get the 1080p screen. This isn’t a huge factor, but it is nice to have and is noticeable in gaming. Since the M15x is so powerful it is actually able to support games at max settings in 1080p and it just looks amazing.

Also, you have the right idea with the battery and storage. 250 GB is what an average person uses in a lifetime so you’re good there. The $ 100 battery upgrade gets you all of 30mins more so you’re good with the 6-cell.

Since that’s kind of messy up there i will add a quick overview of what to change.

Processor: i7-740QM
Memory: 4GB DDR3 @ 1333MHz
Graphics Card: NVIDIA GeForce GTX 260m
(optional) wirless card: INTEL 5300 (AGN compatibility)
(optional) Screen: 1080p resolution (will look noticeably better at max settings than 900p)

*With all of these changes you would pay about $ 250 more, however the performance would be much better and be able to play any game at max settings, including Crysis*

For a video on performance with these specs: http://www.youtube.com/watch?v=KgMPW-HMr5I&feature=related