What are the most entertaining fights that had no knockdowns?

Bowe vs Holyfield I

Froch vs Kessler I

Eubank vs Watson I

Johnson vs Collins

Rios vs Alvarado I

Pacquiao vs Marquez II & III

I'll pop back if I think of some more

Gatti vs Ward 3

Morales vs Barrera 1,3

Morales vs Maidana

Tyson vs Holyfield

Duran vs Leonard 1

Ali vs Frazier 3

Morales vs Barrera 123, although Morales did fall once. Holyfield 123 was great too, although they both did fall once or twice in one of their 3 fights.