Hi,
"In the old days, if you were tying a dry fly, it was a "94840". If you were tying a nymph, it was a "3927B". At least that is my recollection - back when everyone used Mustad hooks.
Now, there are so many to choose from, you might get confused.
Today, I was tying some PMD's for a different post. I was using some size #16 Gaimakatsu P 10 hooks which are labeled "Traditional Dry". I went back to the bench to tie another and reached for a hook. I had a box of 100 TMC hooks there - "101 size 16" and labeled as "Dry Fly Straight eye 1XF". I ordered the TMC hooks from Blue Ribbon Flies and just told them I wanted some standard dry flies.
Anyway, when I put it in my vise, I thought it was a size 14.
Here are the two hooks next to each other: