My experiences with memorex *CDRWs* was aweful. Maybe their CDRs aren't as bad (I think there's a spindle of 30 free ones in a closet at my house SOMEWHERE) but those were total crap. By comparison I haven't had an issue w/ TDKs yet, CDRW.
For CDRs, my preference (although most of these seem to be impossible to find now) has traditionally been:
Ricoh (scratch that nowadays)
Sony
Kodak
...
It doesn't really matter as much now as when I first got my trusty Ricoh 4x write/rewrite drive many years ago.
Kodak is still top on my list, if only I could find some more of their unbranded spindles
