I got the Asus DL DVD drive listed in my sig very cheap ($27) on sale at Staples. Does everything I've tried so far, which is not a lot, I just got it for occasional times when I might want to play/rip a CD or DVD. I've burned a couple of data CDs but no DVDs yet. Seems to read various types of discs no problem. Unit didn't need a hardware-specific driver or software, and it can get enough power from a single USB port on my Mini.
This unit is all I need for now, but later on I might get a Blu-ray drive.