Top drawing matches, year-by-year, 1929-1974
These are the main events of the cards reported to have been the largest draw each year from 1929 to 1977. There are two problems with this list 1) not all cards had an attendance figure reported and 2) the reported numbers weren't always accurate.

I think it's likely that the biggest crowd of the year would be mentioned, so if there was no attendance reported, it was likely not the biggest draw of the year. But there's no guarantee of that, and after 1974 the attendance reports become highly infrequent. The inaccuracy of the numbers could be a bigger issue. Usually the figures in the papers made sense, but sometimes there would be a huge number out of the blue, and occasionally different papers would report completely different crowd sizes, sometimes separated by thousands. But this is the best information available.

Whipper Billy Watson was in the top drawing match 21 times. The Sheik is next with 10.

1929Gus Sonnenberg vs Dan Koloff (9,000)
1930Gus Sonnenberg vs Stanley Stasiak (9,600)
1931Jim Londos vs Gino Garibaldi (15,800 - first Maple Leaf Gardens show)
1932Jim Londos vs George Zaharias (14,350)
1933Jim Browning vs Joe Savoldi (11,000)
1934Jim Londos vs Joe Savoldi (11,000)
1935Dan O'Mahony vs Jim Browning (16,000)
1936Dan O'Mahony vs Ray Steele (9,000)
1937Dan O'Mahony vs Dean Detton (7,000)
1938Masked Marvel (Ted Cox) vs Vic Christie (10,000)
1939Elimination Tournament, won by Vic Christie (6,000)
1940The Angel vs Jerry Monahan (11,000)
1941The Angel vs Masked Wolf (10,000-)
1942The Angel vs Strangler Lewis (10,000)
Whipper Billy Watson vs Wild Bill Longson (10,000)
1943Whipper Billy Watson vs Jack Claybourne (11,000)
1944Whipper Billy Watson vs Hard Boiled Hannigan (12,000)
1945Whipper Billy Watson vs Frank Sexton (10,000-)
1946Whipper Billy Watson vs Wladyslaw Talun (14,000)
1947Whipper Billy Watson vs Wild Bill Longson (15,000)
1948Whipper Billy Watson vs Nanjo Singh (13,000)
1949Whipper Billy Watson vs Masked Marvel (14,000)
1950Whipper Billy Watson vs Yukon Eric (13,000)
1951Whipper Billy Watson vs Lord Athol Layton (14,000)
1952Hans Hermann vs Yukon Eric (13,000)
1953Al Mills/Tiny Mills vs Whipper Billy Watson/Yvon Robert (16,000)
1954Al Mills/Tiny Mills vs Ernie Dusek/Emil Dusek (13,000)
1955Whipper Billy Watson vs Antonino Rocca (13,000)
1956Whipper Billy Watson vs Lou Thesz (15,000)
1957Whipper Billy Watson/Yukon Eric vs Gene Kiniski/Dick Hutton (15,000)
1958Whipper Billy Watson vs Al Bunny Dunlop (13,000)
1959Whipper Billy Watson vs Gorgeous George (14,000)
1960Whipper Billy Watson vs Gene Kiniski (10,000)
1961Bulldog Brower vs Yukon Eric (10,000)
1962Buddy Rogers vs Bruno Sammartino (14,000)
1963Buddy Rogers vs Lou Thesz (11,000)
1964Whipper Billy Watson vs The Beast/Martino Angelo (11,000)
1965Johnny Valentine vs The Sheik (7,000)
1966Masked Yankees vs Whipper Billy Watson/Lord Athol Layton (7,500)
1967Tiger Jeet Singh/Fred Atkins vs Whipper Billy Watson/Mighty Igor (7,500)
1968Ivan Koloff vs Edouard Carpentier (10,000)
1969The Sheik vs Gene Kiniski (15,000)
1970The Sheik vs Whipper Billy Watson (17,000)
1971The Sheik vs Tiger Jeet Singh (18,000)
1972The Sheik vs Carlos Rocha (18,000)
1973The Sheik vs Andre the Giant (18,000)
1974The Sheik vs Andre the Giant (16,000)
1975The Sheik vs Abdullah the Butcher (12,000)
1976The Sheik vs Mark Lewin (8,000)
1977The Sheik vs Tiger Jeet Singh (7,000)