Back in the days of FMV gaming it was pretty common to see amateur actors while playing early CD-ROM titles. Since then though that atheistic has fallen out of fashion to the point now where it's practically unheard of to even see box art featuring images of real people. While I can honestly say I'm glad those dark times are behind us I still think the use of live-action performances has a place in gaming culture. Not in the form of movie adaptations so much as straight up parody works done purely for comedic relief. Here's three example videos of Final Fantasy VII, Streets of Rage, and Doom to illustrate my point:
Incidentally, you might have noticed that the Doom video clip was actually directly from the film adaptation. This is true except for the targeting reticle and the sound effects (which have been changed back to those used in the original game). Personally, I found this a significant improvement to what was already the only interesting part of an otherwise dull movie. I guess it just goes to show you the cheesier it is the more humorous it becomes.