Best English Wordplay/Jokes

Greetings fellow Americans!

For once in my life I'm experiencing being the minority lately, with my status as an American (I'm too used to our domination of Reddit!). I've been running a lot of 5-mans with various western Europeans who presumably work 2nd shift or have insomnia (given the 4-6am server time I play).

I've set the goal for myself to teach these fellow warmaners some of my native english idioms in the best way possible - humor! (it should be noted that I play intoxicated often enough)

At any rate, when I inevitably get left behind in the chatbox full of cyrillic or gaj's latin...I merely start responding with one liners that I can think of. After several attempts, I finally had one fine fellow ask what I meant after one, and he was greatly interested in hearing more.

What are some nice clean (or dirty, I guess I don't care) simple jokes to share that would transcend cultures (i.e. probably nothing to do with our politics or geography)?

• What did the fish say when it runs into a wall? -DAM!
  
• If America changed from Imperial pounds to Metric kilograms overnight, would it create mass confusion?
  
• I just made up a brand new word! -plagiarism!
  
• My mom got upset when I told her a joke about being fat. -She really needs to lighten up!
  
• What did the one tectonic plate say when it ran into the other? -Sorry, that's my fault!