hey ppl i came across a site which like lets u build ur pc online n tells u if the parts r compatible.. but the thing is my 7yr old laptop died a few weeks back n i had it saved on it.now i need to build a desktop so if u can provide me with such a website..
I don't know of what website you're talking about. If you post and provide all the information in the "How to ask for new build advice" sticky at the top of the forum we can build you a system optimized for your intended use and budget. We could do a lot better than an automated website.
What's your budget? What are you wanting to do with the system? That's why MadAdmiral and I suggested posting using the format in the "How to ask for new build advice" sticky. We can't really help without some basic information.
Based strictly on the "best" GPU as you put it, that would be the 5970. That's assuming it will fit in your case.