RAM is not all created the same. I always avoid cheap RAM. In fact, IMHO it's become even more important to get decent memorty with the advent of DDR. It just seeems to be more difficult to make correctly. As with all tech weenies, I have my pet brand (Corsair). But I would say at least get some kind of quality brand. I would include Corsair, Kingston, Crucial, Geil, Apacer, Viking, and Micron among them. It's possible I'm forgetting one or more, but that's a good list to go by.
If you're not looking to overclock, just pick the cheapest RAM among that group that meets the specs you require (i.e., if you need PC2700 don't just get PC2100 and hope).