You got alot of choices. How soon do you need to upgrade? If immediately then get a MSI 790FX or another 770X or 790X board($100-150) with the Phenom 9500($190+), get DDR2 800(cause you can get 2 gigs for $30-35 after rebate). Forget about OC cause Phenom will not OC. This is way you have a quad core system that is versatile for a cheap price plus you also get PCI- Express 2.0. This way for the next couple years all you got to do is upgrade GPUs.
Intel chips blow away AMD CPUs now, if you go with Intel, you can get a P35 board($100), Q6600($270), DDR2 800(30-35). Problem is no PCI-Express 2.0. You got to pay more for a X38 board($200+). Intel with with PCI-E 2.0 will run you +$130 over AMD.
Gaming is still mostly GPU limited so unless you do a lot of number crunching, AMD maybe the way to go for a budget system.
If you really want to get a $200 Mobo I can suggest gigabytes GA-X38-DS4 which can be found at $199. It is the cheapest X38 board out there and it is a quality product. Personally I find the SLI vs Crossfire argument silly unless you need the fastest machine out there. I will never shell out that much money for 2 cards. Eventually they are going to put multiple cores on a chip just like they did CPUs. I think AMD has the edge here cause of the experience the AMD engineers have to offer to the GPU design.