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If you didn't know a benchmark is a standardised test of performance but also at the side it shows the price in USD although you'll find them all in the UK. I'm assuming you are as you have a man city pic there. I have the GTX 260 (ye its old) and I can run skyrim 1920x1080 ultra settings. Not so well BOII, maybe mid-high settings. I'd actually suggest the Radeon HD 7850 as it's quite cheap and from what I've read - very good.
To answer you're question the 660 Ti is really good but much more expensive. If you have the money then consider going for it.
But if you aren't too sure what you're doing (and i'm not saying that you dont) make sure you invest in a good power supply unit.