Well, at the present time I think the Intel cpu's are the best buy, and the sweet spot of performance/price ratio is probably the i5 3570 or i5 3570k if you plan on overclocking. The CoolerMaster Hyper 212 Plus is a reasonably priced aftermarket cpu cooler if you want to overclock.
I've never used an MSI motherboard, so if those are your preference, I don't have any suggestions. I generally use Gigabyte or Asus motherboards, but on my i5 build, I went with an Asrock Z77 Pro 4. It has been running fine, but I do have some issues with the design of the motherboard...its not very convenient with my particular layout. You can probably find a Z77 chipset board with USB3, and 6gb SATA for about $100-120 (US).
8gb of DDR3 ram is probably all you'll need. Buy from good brands like Corsair, Crucial, G.Skill and Kingston.
For an SSD, I'd look at Samsung 830 or 840 series, or Crucial M4. Size of your operating system ssd...well that's a personal choice. I'd get 120-128gb at a minimum. I wound up with a Crucial M4 256gb.
It sounds like your gaming requirements aren't that demanding. I'll let someone else advise you on the video card. By the way, what size and brand of power supply do you have? That could be a very important bit of information.
Video encoding is going to be the most demanding thing you've mentioned. I like to have one hd as source and a second as the target. How much space to get depends on your budget and how you tend to store video. I think you should at least price a 1tb drive, or even a 2tb drive to add to what you have. May not be absolutely necessary, depending on how you use your computer.