I'd check NewEgg.com, or TigerDirect.com and see which brands are on sale. Depending on your budget you can go w/ more extreme modules or more standard ram. The key i think is to stick w/ a good known company. OCZ, Mushkin (the brand i use), Patriot, Crucial (their Ballistix line is very good, but a bit pricey, Kingston & CORSAIR are all good companies. Deals change daily, so i'd see whats available and maybe on sale.
Personally i'd stay away from cheapo no-name-brand RAM. Why risk it when the prices are so relatively low