Filed from 5 published puzzles

THATSIT

Set to 3 different clues across 5 published puzzles, most often "Aha!" — The New York Times, Thursday, 25 December 2003.

7 letters

Every clue on record, most used first

"Aha!"2 times
The New York Times — Thursday, 25 December 2003
"Eureka!"2 times
The New York Times — Friday, 28 December 2001
"All done"once
The New York Times — Tuesday, 18 October 1994

Other answers to these clues

AHA3 letters
FINITO6 letters
GOTCHA6 letters
GOTIT5 letters
IGETIT6 letters
IHAVEIT7 letters
ISEE4 letters
ISEENOW7 letters
IVEGOTIT8 letters
JUSTASITHOUGHT14 letters
OVER4 letters
SUCCESS7 letters