Upgrading system and need some help on Vid cARds

OK so here is are the things I am goin to buy on my new system.

E8400 cpu
4GB 1066 DDR2
500GB HDD
Win Vista
and I will be using my 22in widescreen 1680*1050 max resolution so I want a card that will do its best at that resolution. Now I really dont want to spend alot more for the 4870.
I was thinking of the 4850. Is this card really good to play crysis and such. Or should I save more money and get the 4870 or the GTX 260. I did some research on how this cards have done and I was leaning towards the 4870 but I cant make up my mind since Im just gona be using my 22 at 1680/1050. I stilll cant decide please help what do you think. I dont tend to upgrade for a while maybe till next year but I really do wana play crysis without being like Awww ****.

ps. my previous card is a 1950Pro 512mb