I was thinking of being a bit more precise in my title by mentioning the top contenders in which I am most interesting in getting, but I have decided to be more open so if anyone has any suggestions which aren't of the cards I mention then please feel free to tell me what your thoughts are.
My current system consists of a Phenom II X6 1055T @ 4GHz and my current GPU is the PNY GTX 560Ti. From what I know about bottlenecking I think my CPU should be fine for awhile before I will need to consider upgrading. My ideas for a GPU are at the moment going for either a GTX 670, 680 or a 7970. This is where it gets rather tricky for me as both Nvidia and ATI have their own advantages and disadvantages as such.
I have always preferred Nvidia due to the fact it has many technologies behind it that make gameplay a lot smoother and look a lot better, but as I said I am open to suggestion. My budget is at about £350 to £400 more preferably at the £350 mark. I have also seen some good deals on second hand 6990s and 590s which could also be an option.
What are any of your thoughts on this matter and are there any other options that you think I should consider before buying a new GPU?