I had a college roommate who would watch dubbed anime with English subtitles in order to spot discrepancies between the two. I never understood it, but he got some sort of pleasure from it.

I've always tried to disable subtitles, as I often find them distracting. Especially if there are discrepancies between what is said and what is written. Somewhere in the torturous experience that is Devil May Cry 2, the line "Demons never cry" is spoken when the subtitle reads "Devils never cry". Painfully bad, and I'm sure it happens in better games as well.