Crucial has been making a name for themselves for the past year or two. Head on over to Mikhailtech and see what they have to say about Crucial 256MB PC2100 DDR_RAM. here's a snip:
"The stick itself bears the general characteristics of most units made with Micron chips. it's a 256mb part, PC2100, CL2.5, unbuffered, non-parity, 2.5v, arranged in a 32meg x 64 array. Also, it's the usual 184-pin DIMM with a 64-bit data path. There's no ECC and it's not registered, so don't expect to use more than three of these sticks in a motherboard that has 4 slots (like the Abit KG7-R). Unlike a lot of manufacturers, Crucial memory is made from a 6-layer PCB as opposed to the 4-layer build of the competition. Speaking of competition, I decided to pit it up against another 256mb part I got. I'm referring to the previously reviewed Micron DDR stick."