Zachary's a fine name, but its SO common on boys of all ages where I am, I can think of literally fifteen boys that I know named
Zachary (almost all who are called Zach/Zak/Zack.) So because of that its really plain and boring to me. I like it nice enough though and if it wasn't so widely used where I live, I would probably like it more.
Zacharias and
Zachariah are not my style at all, and I have a bad association with the name
Zachariah.
Zacharias would be cool on the right little boy.