What Intel northbridge(s) do you recommend for current system builds? Thanks,
Max

By ascending order of price and descending order of value:
P31, P45 and X48.

What about, say, the 680i?

680i is Nvidia, not Intel. And 680i sucks.

Sorry, I meant motherboards for Intel procs-so then with that what would be the best northbridges?

Also, in NewEgg search, P31's are supposedly the same as the P35's. Is this true?

P31 - ICH7 - 4G max RAM
P35 - ICH9 - 8G max RAM

So basically between those two pick the p31. I've used it in many builds and it performs and OCs pretty well, no as high as p45 but good enough.

Thanks! Unfortunetly my friend is being stubborn and going for a 680i mobo.

Early 680i boards are known as "ram killer" in that it burns out ram (google it). Later revisions mostly solved that problem. But there are still ram compatibility issues, so be prepared to return ram for a different model. The chipset also runs hot, and you need to keep an eye on temperature, especially if oced. It oc horribly, most people cannot push a g0 q6600 past 2.8ghz on it, compared to the more typical 3.6ghz on p35 and above. That's about it.

That's too bad...

Maybe if I show him that, he'll change his mind

He wants to overclock an e8400 to 4 ghz. Of course, he also wants to do it on stock cooling. What a waste... He'll probably end up frying it when he could've simply bought a nice Arctic Cooling for $25!

If he gets a 680i, he'll learn the hard way.

He should get the P45 instead of the 680i = pain in the neck.