What's a PC without a processor? A heap of parts, that's what. Here's a list of our favorite CPUs from the past year, arranged from least expensive to most.
AMD Athlon II X2 240e - $77
You'll be hard pressed to find a decent CPU that's less expensive than this, yet still worth buying in 2009. Aimed at the low-end consumer who needs only the basics in their new PC, this 2.8GHz chip has no L3 cache, works with AM2+ and AM3 mobos and supports DDR2 or DDR3 memory. At just $77 (or less on the street), it provides enough power to handle most generic tasks--Word processing, web surfing, etc. We wouldn't recommend it for hardcore gaming, but this is likely ideal for your grandmother's new rig. No offense to Granny, of course.
AMD Athlon II X4 620 - $99
Just because you're on a budget, that doesn't mean that you can't nab someone a new piece of silicon for their future machine. The Athlon II X4 620 might be the only modern quad-core processor that you can get with a single $100 bill, but it's no slouch. Featuring a clock speed of 2.60GHz and designed to work in most AM2+ and AM3 motherboards, this chip undercuts every currently available quad and even some triple core processor on the market in cost. In our real-world testing, however, it stood up quite well against the competition. Just think--"budget" doesn't have to mean "low-end."
Intel Core 2 Quad Q8400 - $183
Intel's chips generally aren't the cheapest in the bunch, so it's no surprise to see its first option hit at the mid-range level. The quad-core Q8400 is a real beast at this price point. It's plenty powerful to push out Blu-ray content and handle modern games, yet it won't completely shatter your gift giving fund account. It checks in at 2.66GHz, but is easily overclocked much higher with the right mobo. If you're looking to help someone power their first gaming or Media PC, this CPU is probably a safe bet.
Intel Core i5 750 - $189.99 - $209
Intel Core i5 Processor On The Intel DP55KG "Kingsberg" Motherboard
Intel Core i7-860 - $280
If a Core i7 'Extreme' is too rich for your blood (or just overkill for your Secret Santa recipient), the 2.8GHz Core i7-860 should be a solid substitute. With 8MB of L3 cache and great overclocking potential, this powerful CPU is ideal for A/V editors, multimedia junkies and avid gamers. Best of all, you can sleep easy knowing you didn't pay Core i7 Extreme prices while still nabbing a good majority of that performance.
Intel Core i7 975 Extreme Edition - $999
Whenever Intel throws "Extreme Edition" onto the rear of a CPU's name, you know 2 things: first, it'll be really, really fast and second, it'll be really, really expensive. The Core i7 975 EE is one of Intel's most potent chips, boasting a 3.33GHz core frequency, Turbo Boost, 8MB of L3 cache and a price tag that's higher than some full systems. Only purchase for those willing to give you rides in their Gulfstream, unless you're just loaded, and super kind to boot.