Well I'll be a monkey's uncle!

Nathan's wearing his monkey pajamas tonight. We've joked about how my sister is a monkey's aunt. Which got me thinking....
I haven't said the expression "I'll be a monkey's uncle" in a really long time. In fact, I haven't even thought of it for many years.
What are some other mainstream expressions we used to use but don't anymore? I'm interested to hear what you think dear readers. In the meantime, I'll see what I can conjure up and write about them later.