If you're planning to just add an extra stick of RAM to your existing setup then i suggest you get the exact same module if you can find one or at least the closest one to it. That way you eliminate the possibility of incompatibilities or instability. I'm not saying other brands will not work, as long as you get one with the same spec (PC2700 DDR333), it will but getting the same one would be the safer choice.
Incase you're actually planning to completely change that then you'd have a wider array of choices depending on the usage of your PC. For normal home/office work, internet, etc...i guess generic brands will do. Although, you can also get value versions of branded ones (kingston, geil, corsair, etc.) for durability and flexibility...it'll cost you just a little extra.
If you wanna OC, then that's a different story which i won't bore you with unless that's what you really intend to do. hehe!
