Get a quad-core HP laptop for $385
This refurbished 15.6-inch Pavilion packs a little more power than most laptops priced under $400.
You know the deal with most bargain laptops: lower-end processors, weak graphics, smallish hard drives, and so on.
If you need a little more power than the average low-end lappie affords, check this out: MacMall has the refurbished HP Pavilion g6-1c58dx 15.6-inch laptop for $384.99 shipped.
That price buys you a quad-core AMD A6-3400M processor, 4GB of RAM, a 500GB hard drive, and a 15.6-inch LCD. As my dad often says, that oughta keep you out of mischief.
(Interestingly, OnSale has a 17-inch model, the Pavilion g7-1237dx, for the exact same price--but it has a dual-core processor. All the other specs are virtually identical. So which would you rather have: a bigger screen or a faster processor?)
In addition to the zippy CPU and spacious hard drive, the Pavilion g6-1c58dx offers AMD Radeon HD 6520G "discrete-class" graphics. That's just a fancy marketing term for faster-than-typical-integrated graphics, but don't confuse it with actual discrete graphics hardware. This system should be able to handle midrange games and video chores, but nothing too fancy.
Still, that's better than what you get from most sub-$400 laptops. My only real concern here is with the warranty, which isn't specified anywhere. But I pinged a MacMall sales rep and was told 90 days, which is typical of HP refurbs.
I'm not saying this is a powerhouse PC, merely that it's more powerful than the average bargain laptop. If that fits your particular bill, have at it!
Bonus deal: Yesterday I mentioned the Mac version of Duke Nukem Forever as part of an Amazon game sale. If you're a Windows user, Steam has Duke Nukem Forever (PC) for $4.99. (While you're at it, grab the expansion pack, Duke Nukem Forever: The Doctor Who Cloned Me, for just $2.49.) This endlessly awaited game may have been a disappointment overall, but it's definitely worth five bucks.