* Alan Dean Foster -- Call to Arms, in this case the we are the strong ones.

* Hal Clement -- Nitrogen Fix, replace Nitrogen with CO2 in your head and this could be rather current :)

* An obscure one I liked, but I forgot the Author and Title --

Seems Interstellar Travel could be achieved with 15th Century Tech.

So Aliens landed on late 20th Century Earth with the goal of taking it over. But were easily defeated due to how advanced Earth Tech was compared to what they had. We analyzed their spacecraft and learned how easy it was to achieve interstellar travel. Was a rather interesting read IIRC.