I actually really like stuff like #s 1 and 3, where movies are making improper use of real concepts that are testable and disproven, but come on - pointing out that different alien species can't interbreed isn't impressing anyone (espeically after you've already said that those aliens can't exist anyway). Drop some real science on us instead of trying to poke holes in concepts that obviously rely on the suspension of disbelief in the first place.