Jeez, the fanboy comments are incredible in this thread....just cuz you said AMD!
On a budget, AMD is the way to go...whether the Intel Fanboys want to say it is or not.
Here, you asked for AMD, here's an AMD setup:
Any reputable branded 780g motherboard
Any X2 Processor of your liking (45w CPU's would take less power
2-4GB of your memory of choice (I prefer Corsair or GSkill myself)
GPU of choice
Despite what Intel guys will tell you, that setup will keep up with any similar clocked Intel system...period. Intel starts taking the lead when it comes to overclocking. And come on...if its just for Wow, an AMD will do just fine. Even if its for Crysis, AMD will do fine. We're talking 1-5 FPS difference at MOST between similarly clocked Intel vs. AMD processors.
If you don't mind spending a few more bucks and going Intel, by all means go for it. AMD will be the cheaper route, and will suffice just fine for the purposes you stated.