"I'm do-o-one!"

• Entertainer's word
• "Here I am!"
• Cry made with a curtsy, maybe
• Vocal fanfare
• Bit of verbal fanfare
• Follower of a drum roll
• "And that's it!"
• "The feat is complete!"
• Magic word

Wiktionary Word definitions in Wiktionary
interj. (alternative spelling of ta-da English)