For me, I've decided to drop all the extras for DVD's that I rip. Then I transcode just the feature to MP4 using Handbrake. It's quick and easy, and I can queue up a whole bunch of videos and just let it chug away at them.

I have only started with my DVD's, and have only done a few HD DVDs & Blu-rays. I currently have 5x1TB in RAID 5, ~3.6TB, and only have about 700 GB free. I have plenty that I haven't transcoded yet, and transcoding to MP4 generally cuts the files in half.