Helium Sealed Drives
I love that there are helium sealed drives - this is just an inherently cool thing. Helium sealed drives use less power, are quieter, generate less heat, and are more resistant to dust and debris which can lead to drive failure. Helium is less dense than air, and this allows the drive to spin with less turbulence and take up less power, and also generate less sound through vibrations. The drive operates at a cooler temperature because less friction is caused in the helium environment. Because a Helium drive is smoother and more stable more platters (the circular discs that rotate on a spindle) can be fitted inside the same space. The encasing needed to seal in the helium also keeps out particles than can effect the performance of the drive.
Western Digital currently offers several multi TB helium sealed drives.