Well I'm going to suggest a lot of changes to your build, it will be slightly more expensive but I notice that you didn't include a power supply in your build so the difference in cost really is just the PSU. Here is what I would recommend:
CPU: Intel i3 3220
- Only slightly more than a 2100 and there's really no good reason to go with previous generation equipment for the small difference in cost
Motherboard: ASRock B75 PRO-3M
- I wouldn't touch a Foxconn motherboard with a 200 foot pole much less a board using the old as heck H61 chipset. With a B75 board you get the vast majority of features that a modern board supports
RAM: Corsair XMS3 2x4GB DDR3-1600
- Corsair makes nice RAM but you're way overpaying by going with Dominator RAM for this build
Video Card: Sapphire Radeon HD 7770 GHz Edition
- A Radeon 6670 is weak to say the least and wouldn't do very well driving GW2 and may even have some issues with LoL. A 7770 will be able to handle itself much better than a 6670
Hard Drive: Stuck with the same, would love to add an SSD but the budget you've given really doesn't allow for it
PSU: Corsair CX-500
- You need one in order for your PC to work and if the HEC case you're looking at came with one I still wouldn't trust it
Case: Fractal Design Core 3000
- A far better designed case than the HEC you're looking at.
The speakers, OS, monitor & DVD burner are all fine as is although I would encourage squeezing a bit more out of the budget if possible to see about bumping the video card up to a Radeon 7850 if at all possible. The total cost for my proposed build is $815.89 not including shipping & handling.