Please post your current system specs so that we can get a better picture of your system. I don't even know if you have a pcie2.0 port, nor sata 6GB ports, and I don't know if you have a decent cpu. Also you power supply could be a limiting factor in you getting some video cards.
My strategy for building budget machines for gaming is to get "good enough" memory, hard drives, and CPU. Then focus on a great power supply and video card.
-8GB of memory is needed to properly pc game now. If you skimp out and go with 4GB you will
have to generate a paging file, and that slows everything down by an order of magnitude (or more). Corsair Vengeance 8GB DDR3 1600MHz CL9 Dual Channel Kit (2 x 4GB) at Memory Express
$64.99. This is my generic 1600MHz,8GB kit pick. This changes with time (sales are great).
2GB of video memory
is enough to run these game, although to be future proof you would want 3-6GB, especially if you want to upgrade your monitor sometime.
My recommendation is a 660ti 3GB edition as it is the best one you can afford, and will do a great job in the majority of games. You can get higher frame rates per dollar with ATI, but the stutter is not good right now, and we don't know when (or if) ATI will fix it. eVGA GeForce GTX 660 Ti FTW+ 3GB PCI-E w/ Backplate, Dual DVI, HDMI, DisplayPort at Memory Express
$349.99 with a 10 dollar mail in rebate and comes with metro: first light free!
. This is also an EVGA product, so it's top of the line for nVidia
You cannot afford to go all SSD for storage as it is about $1 per GB, where a mechanical drive is around $.10 per GB. I would recommend a Western Digital Caviar Black 1TB HDD @ 7200 rpm. This drive is very very fast (for a mechanical drive) and it has a frekin' terabyte of space on it. WD 1TB Caviar Black 7200rpm SATA III w/ 64MB Cache at Memory Express
Total: 504.97 before taxes, and a 10 dollar mail in rebate, and a grade A game to play. Seems like a good deal to me :thumb: