If you were an alien watching Earth from space, what would make you go "dude, what's up with that?"?

I watched War of the Worlds yesterday. At the beginning, Morgan Freeman says something along the lines of “dude, what if aliens were watching us and stuff?” (I might be paraphrasing here). That got me thinking, what would aliens find odd about what we do? I’m guessing they would not find war odd (especially since, according to Hollywood, aliens rarely come to just chill), but surely there are things that, if we step back and have a look, are just plain weird. What would you say are some of those things?