Graphics card question

[Squalllionheart]

Hi guys & girls,

I'm looking into upgrading my graphics card, currently cruising with 1GB Geforce 9800GT and while it does the business for all the games I currently own, I want to see the full graphical potential of my games, Skyrim runs on medium settings (apart from some options) and I want to be able to have full detail. I am looking at mainly AMD cards now and have a budget of around £90, I want a card that will provide the best value for money and a card that I won't have to upgrade in the next 2\3 years. I was looking at the Radeon 6770 as it's below my budget and seems to be a decent card, but at the same time I'm sure there are better cards out there such as the 6850 but that's just a little over the budget, any advice out there?

The rest of my spec for reference:

Windows 7 32Bit
Asus M3N78 PRO Motherboard
AMD QuadCore 9950 (2.2Ghz)
DDR2 4GB Ram
650W PSU