Your core building skills should still be going strong. The choices are what's gonna make it tough.
I originally wanted to spec an i5 system for a friend of mine and spend approximately $900 on it. But, in the end, we specced an amazing i7 build for $1100 shipped, including rebates.
There really is a plethora of options and choices you could go with, so it all depends on your needs, your absolute maximum budget (since many people flex on this), and current deals.
An i7 and an Asus P6T motherboard are a great combo, and we used this in my friend's build.
So, wadduya want?