Shiniest or most shiny.
shinier, shiniest
shinier shiniest
Shinner and shinniest
most brilliant
Sleep is a noun and does not have a superlative. Sleepy is an adjective and the superlative is "sleepiest."
The superlative for willing would be "most willing." There is no one-word superlative.
"Studying" is not a superlative, as it is not an adjective. "Most studious" is a superlative of "studious."
"Bib" is a noun and, as such, does not have a superlative form.
most superlative is the superlative form of superlative
Tallest is the superlative.
superlative of quiet