For kicks, I've been adding "gobsmacked" to my regular vocabulary.
Other favorite phrases I like to use include "boy howdy" ("boy flocking howdy" for emphasis), "golly", "by golly". They all add to my western mystique, you see...
You're at the grocery store buying milk and eggs. Do you take the milk that's in the front, or do you reach back for a (presumably) newer carton? Do you take the eggs that are on top?