Western Digital WD5000AZRX Green 500GB internal hard drive (8.9 cm (3.5 inches), 5900rpm, 8,9ms, 64MB Cache) (Personal Computers)
Provided No.1 is the noise with me. This hard drive (and I had many, many) really is virtually inaudible. For this purpose it is also very fast, S-ATA 600 compliant, energy efficient and durable. It is almost impossible for a HDD. Buy recommendation!