Synonyms of 'catchy'
Haunting sounds, images, or words remain in your thoughts because they are very beautiful or sad.
the haunting calls of wild birds
If you describe something as unforgettable, you mean that it is, for example, extremely beautiful, enjoyable, or unusual, so that you remember it for a long time. You can also refer to extremely unpleasant things as unforgettable.
A visit to the Museum is an unforgettable experience.
Thesaurus for catchy from the Collins English Thesaurus
If you describe a tune, name, or advertisement as catchy , you mean that it is attractive and easy to remember.