Right now, I'm hovering at just below 60GB free on a 220GB hard drive that was claimed to be a 250GB. Besides wondering why they're overstating their HD capacity, I'm getting to the point where I'm seriously considering buying myself a 1TB external drive (since getting a new computer with that much memory is out of the question financially).
Once I get it and copy all my files as backup, I might go ahead and clear out those anime series that I don't watch too often, as those videos are what's taking up the lion's share of my disk space. I don't want to delete them till I have them stored elsewhere, though. After all, I might still watch them from time to time.
I might also clear out some of my accumulated fanart once I get it onto a backup drive... those high-resolution pics of Leaf, Pretty Cure, and other anime cuties also take up a good amount of space.