Most TV shows are pressed to DVD in their original recorded format. So, for older TV shows (until the late 90's), they'll be in 480i/29.97 fps. For all movies made since ~1980, they'll be in 480p/24 fps. And for newer TV shows, that were filmed in hi-def, they're usually in 480p/29.97 fps, although some studios might convert to 480p/24 fps, to help them squeeze a bit more onto each disk. Most just add "extras" to the last disk, though, instead of trying to eek out with one fewer disk, since most people expect those extras, these days.