Just under 200GB of pared-down, meticulously organized, tagged, rated, and thumbnailed videos. I've even losslessly edited some of them to cut out unwanted space-wasting scenes (e.g. entire scenes with nobody in it that I liked).
A couple of years ago I went through a massive stash purge because I was keeping videos that I hardly ever (or never) watched. I now only keep videos that I really like, rather than keeping 'ok' or 'so-so' videos. My old collection was cut down by about 2/3 (I deleted about 400GB worth of files).
I am quite picky, and I have a hell of a time finding any videos that I like, so my collection grows slowly. I might keep 1 video out of every 20 downloads (and that's despite the fact that I don't download indiscriminately).
I don't have that many videos in total now (approximately 140). The folder size is accounted for by the fact that I prefer hi-res videos, so most of my videos are well over 1GB each.