I have used Hyundai DDR modules, here in Korea. I believe Hyundai chips are also used on Mushkin modules.
They are pretty good as long as you don't do some insane overclocking.
I also used Crucial modules, and the two performs almost exactly the same.
Crucial overclocks better though.
It's your choice... if you want FSB overclock and CL2, go for Crucial. If not, Hyundai is good too.
By the way, the one who make cars is Hyundai Motor Company.
The memory is made by Hyundai Electronics Industries, and recently changed its name to Hynix Semiconductor.