Are you asking about the film with the best production values or about the best (most exciting?) fight of which a film has survived?
1930s - Tony Canzoneri vs Kid Chocolate 1 1940s - Drawing a blank here 1950s -Archie Moore vs Yvon Durrele I 1960s -Chartchai Chionoi vs Effren Torres I 1970s- Matthew Saad Muhammad vs Marvin Johnson 1 1980s -Bobby Chacon vs Bazooka Limon IV 1990s - Robert Quiroga vs Akeem Anifowoshi 2000s - Erik Morales vs Marco Antonio Barrera I 2010s - Juan Manuel Marquez vs Manny Pacquiao IV I made this off the top of my head. I will probably change this later.
Great list. I wouldn't argue strongly against any of these choices, even if they wouldn't all be the ones I'd pick (some are, though). 1940s? Maybe Louis-Conn 1 as there's enough of it on film to include (just a shame we don't have all 13 rounds).
1930s - Tony Canzoneri V Kid Chocolate 1 1940s - Manuel Ortiz V Luis Castillo 3 1950s - Satterfield V Rex Layne 1960s - Gaspar Ortega V Charley Scott 1970s - Victor Galindez V Richie Kates 1 1980s - Rafael Limon V Bobby Chacon 4 1990s - Robert Quiroga V Akeem Anifowoshi 2000s - Erik Morales V Marco Antonio Barrera 1 2010s - JMM V Pacquaio 4 I know it’s a bit late sending this list but yeah hope my list was alright