What's the best day to go to avoid a crowd

Any weekday before noon.

it will always be somewhat busy, but around mid morning on a Monday or Tuesday would be great

Any weekday

I was going to say, we even went on a Saturday at noon and it wasn't too busy because some were leaving for lunch. The place opens at 10am on a Saturday, but I would definitely go on a weekday. My kids had lots of fun.

Anytime before noon.