I can remember that the first PC we had had a hard drive that was 1.2 gig, and was reckoned to be massive!
Now we are into terabyte sizes. And the PC's are faster these days, so the larger sizes tend not to slow down the PC by any large degree.
A handy thing too, is that now we can get cases that use regular hard drives and make them into plug-in external drives, which are great for storing larger data things like movies etc.