Help Picking Parts

Hello,
I am going to be upgrading my computer a while down the road and I was trying to get a basic feel for how much it will cost me
So I was wondering if I could get the fastest card for around 400-450.

I will want this card to last me at least a year or two no problem handling games.

Having the settings on max I really do care about, right now i have a HD 6850.

I have no preferences for the brand GTX,AMD etc.

Thank you for your time!