For the RAM, I strongly suggest Corsair. IMO, it's the best out there (for DDR2). It's kind of lacking in the DDR3 department.
I am currently running an E6600 with 4GB of Corsair XMS2 DHX (DDR2-800) on my P5B Deluxe motherboard. It was a great upgrade over my Wintec
The only reason I would consider any other brand is for rebates. I know I'm only talking about Corsair, but OCZ can be great as well, but there are so many quality grades that it's easy to get screwed. I just ordered 4GB of DDR3-1333 OCZ Gold, even though it's nearly the cheapest memory out there, the timings are loose and the OCZ Gold have a really bad reputation for overclocking capabilities.
** I got these because of the price. It cost me 105$ CAD including shipping and taxes, for 4 1GB sticks. I'll just get DDR3-2000 when it cools down a bit. This is temporary.
If you're in the US, get this.
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145214
The Corsair Dominator is usually overrated, but with the rebate going on, I strongly recommend it.