Most Re-watchable Genre?

[toef]

As simple as the title states. Particularly when paying a hefty price for BD's, the "re-watchability" of a particular movie can factor into the purchasing decision. Of course this varies from movie to movie, but which genre, in general, do you find most re-watchable?

Since there is considerable overlap between some (e.g., war movies can be both action and drama), I'm going to stick to the basics.