<< Crucial, Mushkin, or Corsair. They all make excellent memory. Corsair is usually priced higher than the others. Crucial often has some of the best prices for memory in it's class. >>
Corsair doesn't offer it's higher performing memory in 512mb DIMMs, nor does Mushkin. Hence, their 512mb DIMMs are not better or much more expensive. Crucial does not have excellent memory prices for its class, as Kingston memory is usually cheaper, and has relatively equivalent quality.