If you're looking to (re)build a PC, and especially if you're planning on getting an AMD CPU, Micro Center is the place to go if you have a store nearby. (While they sell stuff online, this is in store only, though you can reserve for in store pickup).
http://www.microcenter.com/specials/...ndlePROMO.html
No end date listed and it's been going on for over a month, but I made sure to get in on it a couple weeks ago with the Phenom II X4 840 and free Asus motherboard. They beat
NewEgg and Tiger Direct's prices on the CPUs in the first place, so this is a fantastic deal. You'd pay about the same price for the lowest priced boxed Sempron and lowest priced compatible motherboard at
NewEgg as you would for the Phenom II X2 that is the lowest priced CPU included in the offer. And then for $8 more is the X4 I opted to pick up, followed by several more 4 and 6 core options.
If you're looking for Intel Core CPUs they have some bundle deals regularly but not as an ongoing promotion. Still, keep an eye on their site, because when the deals are live, they do trump NewEgg, sometimes by a lot.