Upgrade time - GPU the answer?

[Operation]

Hi guys.

My system is getting old and wasn't very high spec to start with. I'm running an i5 2500K at about 4.2ghz and have a 6950 with 6970 shaders unlocked. I'm getting back into my games after a year or so off and wondered how best to spend up to £200 (or maybe 10% extra) to give me a boost. I'm assuming the GPU is the best bet.

A 280, 280x, 290? A 770, a cheapo 780, or break the bank for a 970? I have no idea where the value lies unfortunately and would appreciate some help.

Thanks

 

[Operation]

Cheers. So the 780 is preferable to the 970?
I know there is a major cost difference but is the extra performance good value?

 

[Operation]

Thanks. The temp and noise increase are putting me off.

 

[Operation]

Yes it does seems like the 970 is the way to go. More than I want to spend but seems like a genuine step up over the others that will hopefully delays next GPU upgrade a bit. Thanks for the help guys.