I just delete the episodes as soon as I finish watching.
This is how everybody should be doing, and if you really like it, support the artist and buy the blueray/DVD. If it's meh then a fansub would do I guess.
How many Anime DVD's do I own you say?
Over
nine one thousand. But the collector's instinct in me won't let me take the "delete upon watching" route, unless I really hate the show. That's also why I generally don't watch streams. Plus a lot of shows don't come out on R1 DVD/BD, and I'm not about to go paying obscene R2 prices + shipping for imports. At least not until the Japanese stop bitching about reverse importation of R1 discs to Japan. Actually, I will delete R1DVD-rips for shows I buy on DVD, since the files are just redundant at that point. However, I do keep fansubs around, since they offer different and sometimes better translation and presentation from what you get on DVD.
Besides, if everybody followed the "delete upon watching" principle, how would we have thriving BitTorrent trackers and communities like this one?