Name them, I'll start with an obvious one in Mayweather v Pacquiao. Remember these don't necessarily mean the biggest money generating fights, I mean the most eagerly awaited fights that captured the publics imagination before they took place
The biggest build-up to any fight in my time as a fan was Mike Tyson (undefeated unified WBC-WBA & IBF champ) versus Michael Spinks (undefeated lineal champ). Massive build-up & hype for that one. The fight itself is worthy of mention as the biggest anti-climax in history. It was billed as only the second time in history that two legitimate & undefeated Heavyweight Champions of the World faced each other. The other being the original Ali v Frazier which was known as the Fight of the Century. So that's two for the list.
One from them: Foreman vs Frazier I st fight: iconic damn mark value fight. Piece from boxing heaven. Next: Sonny Liston vs Ali I st fight. One next: Floyd Patterson vs Johanson I st fight.
Hagler vs Leonard Ali vs Frazier Ali vs Foreman Leonard vs Duran May vs Pac DLH vs May DLH vs Pac Tyson vs Spinks Holyfield vs Tyson II Golovkin vs Canelo I and II Wilder vs Fury I and II