What I really liked about this movie is that the aliens weren't overpowered. In alien-invasion type movies, I think it's pretty much expected that the humans are going to win. Few want to watch a movie in which the human race succumbs to hostile aliens. In most alien-invasion movies, the aliens are incredibly advanced, technologically, physically, or both. So when the humans do finally win, they usually do it in some unrealistic or even downright retarded way (see Independence Day, Signs, etc.)
When the group of humans win in Battle: Los Angeles, it feels like they earned it.