I'll go back to my ex and tell her: "Who's the looser now?" and then... well, I guess nothing much more: if aliens are to be human-like and can bear our atmosphere, then we have to expect mass destruction and death (we won't really stand a chance with them being able to cross all that distance when we're still sticked on our little space-rock) and then centuries of slavery, apartheid and freedom/equality movements to get a mixed pseudo-subculture between our conquerors and the last, shattered and tamed generations of mankind... if they're non oxygen-breathing and or carbon-based lifeform, it will be a painful mass extinction (if short of long will depend how funny, or tasty, may we result to them).
One last option is to hope that aliens will respond to the 1st common and fundamental rule of all human Sci-Fi productions: "God created aliens to demonstrate the superiority of mankind!"