Josh12345 said:
5. We encounter religious nuts who believes our very existance offends their gods,a la Halo(bar the Halocaust ringworlds)
I never understood this aspect of Halo. What makes Humans so repugnant that The Prophets want us dead? The took in the Brutes, the worms that make up Hunters and, Scarabs, the Grunts, why not humans? Also, why is it that humanity never encountered another species rejected by The Prophets (other than The Flood I mean). It could have worked out better than the whole brute-elite falling out I think.
back on topic:
Any species that has mastered interstellar travel will either be
A) conquers who will raze our planet and strip it of resources or,
B) Smart enough to know that if they mess with us too much, it'll screw our society up
That being said, I would think first contact would either be sudden, loud and, quick (former) or, quiet and taking place between select individuals (later)
I would much rather have Aliens be here right now, trading silicon for corn peacefully and quietly than to have Darth Malak glass the Earth from above because we are unwittingly harboring the fallen Darth Revan. Honestly though I wouldn't be surprised if either one happened.