probably dx12 wiil come with the next gen MS console and OS.

i have also the same problem. when i play the game at that time i thought that there are some problem in my copy(or installation problem) so i just play that much and uninstallthe game(90% completed). i still not play it second time.

$300(min) to build a gaming rig that able to play recent games.If you want to max out game setting then you must go for high budget(e.g $600).as you mention you want to play game like crysis 2.it is amost CPU and GPU intance games.so you have to get a high end processor and graphics card to gear up your gameplay.

you may choose games like prince of persia(action/adventure)series,call of duty(1st person shooter)series.

I have 2 X GeforceGTX 260 with AMD phenom II x4 965 Black Edition 3.2GHz. i am able to run Crysis on full detail with AA.

Tom's hardware is best for all computer hardware reviews but specially for Graphics cards i recommend www.gpureviews.com.

If you travel more then Alienware Notebook is a good choice. But other than that you choose a desktop with high end and latest hardware.

Motherboard: Asus M4N98TD-EVO
Processor: AMD Phenom II X4 965 Black Edition 3.2 Ghz
Ram: 2 X 4Gb DDR3 1333Mhz
GPU: 2 X Geforce GTX 295 (asus is a good choice)
HDD: 1Tb SATA 7500RPM
ODD: Blue Ray drive (asus is a good choice)
PSU: cooler master 850W
CPU COOLER: Cooler master V10

Its just a above medium level Gaming rig

prince of persia warrior within is best for me

medal of honor by Linkin park

prince of persia by godsmack

according to gener i have sorted the best games

Racing: NFS:mostwanted,NFS:Undercover

Action Adventure: Prince of persia The two thrones

sci-fi shooter: crysis, ghost recon, rainbow six and more

Adventure:Madagascar:escape to africa