honestly.... the difference in prices between quad and dual core now are weird... u can get a core 2 extreme, or for half the price get a quad core.. or go all out and get the quad core extreme. BUT, in my opinion, if you're trying to overclock, get the quad or the duo.. but if quad, not less than 2.66. if core duo, then not less than 2.0. Mobo does matter, but as previously stated, Asus is king, EVGA/Nvidia is next up. If youre doing multi thread stuff get quad core, if you just want a "fast PC" get core 2.. reason being, u may use apps that can't take advantage of ure 3rd and 4th core. Also, many games can only see 2 cores... so if you're a run of the mill gamer and don't do rendering then get core 2.. and at that, u can save a lot of $$ by getting an OK one, or, u can say F@!# the money and go all out and get a sick core duo and OC it to death. It depends on what you're doing. I got quad core, but i NEED it when I render in 3d, it saves me hours and hours and hours of time. hit me up.