I want to be able to play Planetside 2 on high/ultra at a nice framerate.
I currently have an i3 2120 SB
1 GB HD 6770
8Gb's of 1333mhz RAM
A Gigabyte H61 M-ATX Board
A 64GB OCZ Agility SSD
a 500w PSU
A 750GB hitachi deskstar HDD
I've got £300 to spend on upgrades, what should I do? ( I'm happy with my mouse and keyboard )
I'm not in position to advise you since I've never touched the newer generation cards, but I suggest you'd upgrade your video card to either an AMD HD 7870 or an nvidia 660 (or 670 but I guess you have higher price in pounds). I wouldn't reccomend crossfire with your PSU, it's quieter and more efficient and less hassle with one.
I'm just letting you know that Planetside2 runs around 30 fps even on the 670 because the game is optimized well. BF3 runs better on ultra than planetside2 and BF3 is an amazing looking game.
That i3 might hold you back, bit I'd recommend upgrading the card to a 7870, 7950 or 7970 depending on the price.
To play planetside 2 on ultra? you'd need at least a 7970....