I think in the x-files the aliens win.
You know, talking about realistic alien invasions, a physicist claimed that the ships in Independence day are not even THAT unrealistic, given the conditions in space, because it is much more likely to have a really big space ship survive in space rather then small ones, from all we know so far. Because of radiation, thick walls help to protect you here a lot, particularly when you move at very high speed, like close to light speed. It is also much easier to simulate the effects of gravity by rotation in a large space ship, infact they need a minimum size for the rotation to work, a couple of 100 meters if I remember correctly, otherwise ... it will simply rotate to fast. It also helps to store all the food, equipment etc. when you have a really large space craft. Though what he really complained about was the effects those ships had on earth, or well the lack of it in the movie. The effect he was talking about was gravity. The biggest ship in the movie, had 1/4 the size of the moon, or something? With beeing in 30-40km orbit from earth. The size of it alone would have a similar effect on earth like the moon, like it does with the tides. Or the smaller vessels that start to destroy all the cities in the movie. Even their size is big enough have some effect. Infact they would not even need their weapons to destroy the cities. They are so large, they would compress the air, and thus destroy all buildings.
From the technology, yeah, its pretty clear that we would have no real chance to stand our ground against a species that has the technology to eventually fold time and space and not only surviving out there but moving from galaxy to galaxy. Or even traveling between the stars in a timeframe that is acceptable.
