"The whole kit and kaboodle" is commonly used, but actually wrong. "Kaboodle" is a contraction of "kit and boodle", a tradesman's bag and tools. So the common expression is redundant.
I always say "odds and ends", which is a bit silly in itself. As George Carlin noted, if you have 24 odds and ends on a table, and 23 fall off, what's left, an odd or an end?
One that gets me is when someone says MRA for MRI.

One is a medical procedure, the other is a was department store here.
Another one (and no, it's not a "saying" either!): i.e. vs e.g. Contrary to popular belief, they don't mean the same thing.