Here are a few for consideration, including The Brawl in Montreal: Welterweight: Johnny Bratton-Charley Fusari (1951) Kid Gavilan-Gil Turner (1952) Carmen Basilio-Tony DeMarco 2 (1955) Carmen Basilio-Johnny Saxton 2 (1956) Gaspar Ortega-Benny Paret 1 (1959) Emile Griffith-Benny Paret 3 (1962) Charley Scott-Gaspar Ortega 1 (1962) Pipino Cuevas-Angel Espada 2 (1977) Carlos Palomino-Armando Muniz 1 (1977) Pipino Cuevas-Harold Weston (1979) Sugar Ray Leonard-Wilfred Benitez (1979) [Roberto Duran-Sugar Ray Leonard 1 (1980) Sugar Ray Leonard-Thomas Hearns 1 (1981) Tyrone Trice-Simon Brown 1 (1988) Aaron Davis-Mark Breland (1990) Ike Quartey-Crisanto Espana (1994) Felix Trinidad-Yori Boy Campas (1994) Shane Mosley-Oscar De La Hoya 1 (2000) Antonio Margarito-Miguel Cotto 1 (2008) Juan Manuel Marquez-Manny Pacquiao 4 (2012)
I've seen many other great welterweight fights. It is possibly the most exciting division of all time. However I will say as of 1953 the three best welterweight fights on film are Gavilan vs. Turner, Gavilan vs. Bratton II, and Bratton vs. Fusari.
Give me Leonard-Hearns I for the drama, shifts in strategy and momentum and magnitude of the two best welterweights in the world — and arguably the two best P4P at the time — going at it.
You can make an argument for the Brawl in Montreal being the best fight of all time. You can argue it was one of the best welters of all time in his prime against the best lightweight of all time in his prime. It was fought at an insanely high level.