I wouldnt buy a socket 775 system for a new build now.
Listen to this guy, he knows.
I nearly went for a Q8400 powered system, really really glad I didn't now! Having DDR3 and the latest AMD processor was definately worth it.
alright guys, i'll go for i5
will this G.skill ram work ok with the motherboard?
I'd go for a Asus motherboard to be honest, apparantly they're better for overclocking than Geforce ones, and I can't fault mine at all, my Phenom II 965 BE is overclocked to 3.8ghz now, and it's totally stable, which makes me happy!
So personally, I'd go for Phenom II 965 BE if I were you, from what I've read they're similar in performance to the i5s, but they're called "Black Edition".
But then again, from what I've read the i5 is easier to reach 4ghz with. Anything over about 3.8ghz and the Phenom II 965 needs a massive voltage, mines already at the general consensus for the max safe voltage, (1.55v), and I can't get it over 3.8ghz at all.

I tried upping the frequency 5mhz, but it wasn't having any of it.