What event had the most memorable undercard?

yes, the rematches was awesome, 1993 brought quite a few shocks, so 1994 had the potential to bring some solid returns......

 

The one where Larry Holmes fought Leon Spinks, where a couple of youngbloods named Page and Dokes wreaked havoc with the competition.

 

The Hearns-Benitez fight in '82 in New Orleans. The event was called the Carnnival of Champions. The Wilfredo Gomez-Lupe Pintor fight on the undercard was a masterpiece.

 

Considering the crap undercards that we have been offered lately it would be a gift from promoters to see cards like the "old days" again.
It would not be that more expensive to give fans some of their money's worth.

 

chavez vs delhoya 2 from historical perspective not that relevant but hector quiroz vs antonio diaz fight was incredable an made a lack luster main event seem not that bad

 

Well the most recent great undercard probably was Mayweather-Marquez because of the Chris John-Rocky Juarez II fight. That fight easily could have headlined a HBO WCB card.