I've never cared much for HDD space, even if it's cheap I tend to never come close to using all of it.
I have my original laptop which is either 80 or 160 GB, it's needed a new motherboard for a while know so I many never know.
My second laptop has 640 GB, which I considered infinite space at the time. As of now after 1-2 reformats and demoting this laptop to my travel computer/semi-backup drive, I've only used about 2/3 the space available.
My latest laptop has a 1 TB drive that I almost filled by using data recovery software that for some reason duplicated the data it recovered. So with 2-3 copies of some large files or folders, I reached near 900 GB. After going through and sorting the duplicates, I'm sitting around 1/3 full.
The previously mentioned data recovery issue lead to me to buy an external drive that I can't remember the size of. I think it's 2 TB.
I'm planning on buying a desktop. SSD required, probably shooting for 256 GB at least. HDD for bulk storage I'll probably go for 1 TB or more.
I have 3 primary USB sticks, one is 64 GB, the second is 32, and the last is 8. I've got a bunch of random smaller ones too from friends as gifts, from job fairs, from school, etc.
If I can count stuff from the office, I have access to a 1.5 PB drive. All too easy to fill.