For music and audio professionals, we live and die by our DAW and that means everything attached to it as well.
Recently the backup company Backblaze evaluated their more than 41,000 drives and found that 3 Terabyte hard drives had a fairly high failure rate as compared to any other size.
There's also some evidence that regular old consumer drives are at least as reliable and maybe even more so than the higher priced enterprise drives. Also that Hitachi drives were the most reliable, followed by Western Digital with the least reliable being the Seagate.
What's should you buy? The company recommends 4 TB drives (like this one) for both value and reliability.
2 TB drives are a real bargain now as well. Be sure to buy 2 (one for backup).