Which one should i get

Well again depends on the screen size u play...
For a 22" monitor or below, the 4870 is gud...
For a 24" monitor or higher, the 285 is best...

Both the 280 and the 285 are some wat the same...actually the 285 is the replacement of the 280...The 285 has a smaller die size, hence less heat dissipation...So if u have a very well ventilated case, and not willing to spend the extra cash then go wit 280 else go wit the 285...