Answer:

AHA

Answer	Crossword Clue
AHA	"Caught you!"
AHA	"Gotcha!"
AHA	"So that's it!"

AHA	"So! It's you!"
AHA	Cry of discovery
AHA	Triumphant cry
AHA	"Gotcha!" (1-2)
AHA	Cry to the cookie-jar raider
AHA	Discovery word
AHA	Exclamation
AHA	Exclamation of understanding

AHA	Insight response
AHA	Palindromic exclamation
AHA	Sherlock's shout
AHA	Solver's shout
AHA	"So, it's YOU!"
AHA	"The light dawns!"
AHA	"There you are!"
AHA	Eureka!

AHA	Exclamation of triumph
AHA	Exclamation!
AHA	Gotcha!
AHA	Sound of discovery
AHA	"Eureka!"
AHA	"NOW I get it!"
AHA	"Got it!"
AHA	"I found it!"

AHA	"THAT'S the answer!"
AHA	Alan Partridge catchphrase meaning "Eureka!"
AHA	Breakthrough exclamation
AHA	Breakthrough phrase
AHA	"So it WAS you!"
AHA	"Now I see it"
AHA	"You can't fool me!"
AHA	"Caught ya!"

AHA	(missing clue)
AHA	Brainstorm announcement
AHA	"I get it!"
AHA	Puzzle solver's cry
AHA	"So!"