Stay away from Creative Labs. I have a Creative Infra 48x, and it sounds like it is going to explode when reading a disc. I've just ordered a Toshiba 48x to replace my Creative drive.
I've been reading user reviews of Kenwood drives. Kenwood drives break too easily and fail to read many CD-R and CD-RW. I would avoid Kenwood.
From what I've read so far, Asus, Teac, and Toshiba make fast and reliable IDE CD drives. Asus drives are somewhat louder, but not too horribly annoying. Asus has the best data/audio extraction. Toshiba is the weakest of the three in data/audio extraction but reads almost any CD, CD-R, and CD-RW out there. And Toshiba is quiet. Teac seems to be the compromise between Asus and Toshiba.