* Delightful is already a positive adjective, meaning very pleasant or enjoyable.
* More delightful is the comparative form, used when comparing two things.
* Most delightful is the superlative form, used when comparing three or more things.
Example:
* "This cake is delightful."
* "This cake is more delightful than the one I had yesterday."
* "This cake is the most delightful cake I've ever tasted."