One of the things I prize most on the bonus features of Blu-ray's and DVD's are the commentaries. I just get a kick out of learning all the behind the scenes stuff and the hijinks that went on between takes.
My wife doesn't share this hobby. She figures watching the movie as it was made is good enough for her. She doesn't need the epic history behind it, the jokes between cast and crew.
Needless to say, I'm not introducing her to Mystery Science Theater 3000, let alone RiffTrax. I can see it now. We're watching the film, and then the black silhouettes start talking. Wife stands and waves her clenched fist at the screen:
"I'm trying to watch the movie! Don't they ever shut up?!"