Just what the question says on the tin. This is about your feelings, regardless of whether those feelings align with conventional ideas of number bigness or not. Please answer seriously. If you smile while answering, delete your account.
If this looks interesting to you, check out the #Numberfeels category! This poll is being used to resolve this market:
Here are my thoughts:
911 - the date of a national tragedy and an emergency number, doesn't feel like a real number
666 - demon stuff
777 - lucky
912 - doesn't have associated meanings, so it feels the most "number". 9XX feels pretty large
888 - betting?
Fortune 500 - a list of companies
If I were to rank them from biggest to smallest it would be:
912
888 ~= 777
Fortune 500
911 and 666 just don't "feel like" number numbers to me.