mine are:

1.rocky marciano

2.george foreman

3.muhammad ali

3.archie moore

5.mike tyson

Muhammad Ali

Ezzard Charles

Jack Dempsey

Harold Johnson

Archie Moore

Muhammad Ali

Sugar Ray Robinson

Sugar Ray Leonard

Flash Elorde

Ruben Olivares

I'm not sure how you view Old-time but since you listed Tyson, I'll just assume you mean fighters before 1990 or so. My definition varies slightly and would certainly mean fighters before Tyson.

1. Muhammad ALI. Too many reasons to list

2. Sugar Ray Robinson: Nothing was smoother. There was never a more complete fighter.

3. Roberto Duran: Again, too many reasons to list

.

4. Joe Louis: The most Fundamentally Correct heavyweight and boxing's greatest finisher.

5. Ray Leonard/Salvador Sanchez: I miss Sanchez. I'm still a huge Leonard fan but I didn't care for his politics during the second half of his career.

I guess it depends on your definition of old time. I kinda view Tyson as modern era.

Anyway, I would say

1) Ali

2) Leonard, Sugar Ray

3) Wilfred Benitez

4) Ray Robinson

5) Carmen Basilio

If we are talking older than my birth fighters...

1) Ali

2) Robinson

3) Basilio

4) Johnson, Jack

5) Louis/ Pep

Chavez Sr

Finito Lopez

Salvador Sanchez

Pernell Whitaker

1-Larry Holmes

2-Whitaker

3-Nicolino Locche

4-Aaron Pyor

5-Vicente Saldivar

Ali

Cassius Clay - man, that guy was smooth.

mine are:

1.rocky marciano

2.george foreman

3.muhammad ali

3.archie moore

5.mike tyson