I have used OCZ PC2400 and Corsair PC2400 rated at cas 2. The both run 166MHz+ at cas 2. I have used two crusty generic sticks of PC2100 rated at cas 2.5. The both ran fine at 133MHz cas 2, however I did not try running them on a higher fsb. I also bought a stick of Crucial PC2100 rated at cas 2.5, it also hit 166MHz+ at cas 2. I would just find the cheapest Crucial you can, unless you plan to run higher than 166MHz, then get some Samsung.