The answers to the 21 questions are spoilers for the surprises in, in alphabetical order: Citizen Kane, Clue, Dallas, The 11th Hour, Harry Potter and the Half-Blood Prince, The Hound of the Baskervilles, The Murder of Roger Ackroyd, Murder on the Orient Express, The Purloined Letter, The Real Inspector Hound, Rear Window, Reservoir Dogs, Second Foundation, The Simpsons, Soylent Green, A Study in Emerald, The 25th Annual Putnam County Spelling Bee, The Usual Suspects, Watchmen, The Westing Game, and Who Framed Roger Rabbit?
All of the spoilers can be found in the wordsearch grid, but to prevent people from casually glancing at the grid and being inadvertently spoiled, all the spoilers have been encoded by Rot-13 (that is, A -> N, B -> O, and so on; this is the standard way of concealing spoilers on Usenet and other places).
Once you have found all the spoilers in the grid, the remaining letters spell out:
IN THE MYSTERY HUNT BASED ON MONOPOLY WHAT ANSWER SIGNIFIED NEW YORK AVE
The answer to this question is GUGGENHEIM, and that's the answer to the puzzle.
The spoilers themselves, for the curious, can be found below in the forms in which they appear in the grid:
T H I S I S A B U N C H O F S P O I L E R S P A C E B E C A U S E I ' M S I C K O F R O T - 1 3
SLED MR GREEN KRISTIN SHEPARD KILROY SNAPE STAPLETON DR SHEPPARD EVERYONE IN PLAIN SIGHT PUCKERIDGE YES MR ORANGE TRANTOR MAGGIE SIMPSON PEOPLE WATSON WILLIAM BARFEE VERBAL KINT OZYMANDIAS BERTHE ERICA CROW JUDGE DOOM
2006 MIT Mystery Hunt