Currently running AMD Phenom X4 955, 4GB DDR3 and an HD4870. The set-up's lasted surprisingly well - it runs TW2 near maxed @1920 x 1080 and gives playable performance. With the next generation of games coming, though, and having purchased BF3, I'm thinking of upgrading incrementally (I've never seen such see-saw performance as with BF3. In smaller maps with fewer players it runs at high fairly well, but in others it only just copes on the lowest settings).
I've been thinking of going specifically GPU for the moment, with an aim to maximize performance to cost. I've had my eye on the HD5970 and 580GTX, and would rather keep the figure as far below £300 if possible, but I'd be willing to stretch to it (the more I save, the quicker I can upgrade mobo/CPU).
Thoughts on which cards provide the best performance for money?