Cars is a great another animated movie that is very good. Others including; Batman, The Dark Night (unless the violence is too much for your audience), the same for Band of Brothers. Twister is fun with the wind (and cows) flying around. Pearl Harbor (the version with Ben Affleck) is also very good for both PQ & AQ, and even though it is a war movie, it is not real graphic. U-571 also has some good demo stuff.
BTW - - You keep writing "DVD," I assume that you are really looking for Blu-ray disks; correct?