Motherboard - Asus and Shuttle, if its a AMD based motherboard NVIDIA is what I would buy, for Intel, I will use a Intel chipset. I would steer clear from VIA, they're garage in my opinion.
Ram - Corsair and Geil is what I use both are awesome
Videocard - I'm happy with Nvidia more, but ATI is ok, I have a laptop that uses a ATI x1600 and runs games fine for me.
Hard drive- Western Digital and Seagate to me are the best brands.