IMO, name brand does matter for RAM, provided you want full support. If you are piecing together a machine that you don't care about, then RAM brand doesn't matter, just whatever works. However, since most people care about the machine they piece together, they most often reach for the name brand because that brand will provide technical and warranty support if need be.
Quite honestly, the brand name you want to look for is the actual name stamped on each RAM chip. Kingston makes their own RAM chips, but sometimes they use Samsung, Infineon, or some other manufacturer's chips. Buffalo Technology, on the other hand, does not produce their own chips, therefore they rely on other manufacturer's such as Samsung, Micron, Winbond, etc. Crucial does not make their own chips either, they use Micron chips.
So, to recap, pay close attention to the names on the chips. With some name brands such as Kingston and Crucial, you know you'll be getting high quality RAM because they only use name brand chips. Plus, you get their great service and support. With an OEM Samsung RAM stick, for example, you won't get the same support as Kingston or Crucial, but you may get some support through Samsung directly. Just make sure the stick comes with a warranty.
Here are some brands I trust, these are brands that make RAM chips (in no particular order):
Spectek (division of Micron)
Elixir (division of Nanya)
Hynix (division of Hyundai)
I would add Corsair to the list, but I don't know if they make their own chips. Their high-performance sticks always have heat spreaders, so I can't see what name is printed on the chips! Argh!
No, I like women.