We don't often feature power supplies in our deal posts, because PSU prices don't oscillate much, and "bargain" PSUs are typically unreliable and failure-prone. However, Newegg is currently running a very interesting deal on an actually good power supply: Antec's 500W EarthWatts EA500.
In spite of the $89.99 suggested retail price, Newegg sells the unit for only $54.99 shipped. And that's not all. Toss in the coupon code, "PSU8028" (without the quotes), and you can shave down the price to just $44. That's pretty darn cheap for a PSU with an 80% efficiency rating, quiet cooling, and 79% of Newegg customers giving it five-star reviews.
If you already have a good PSU and would rather beef up your PC's graphics, Newegg also sells PNY's VCG88512GXEB-FLB GeForce 8800 GT for $109.99 shipped. The card has stock clock speeds, a three-year warranty, and a copy of Frontlines: Fuel of War bundled with it. (Thanks to SlickDeals for the PSU coupon tip.)