If I remember correctly:

- Lupertazzi;
- Paglieri;
- Mangano;
- Tarese;
- ???

In this scene Sack says that one of the other bosses, "Andy", is his brother-in-law. So that would mean that the fifth family is the Infante family.

Does anyone have any more info?

I've seen references to a DeBenedetto family as the fifth NY family. I always took "Andy" to mean John's sister's husband, otherwise why would he have had to use that nebbish Anthony the Optometrist as a messenger?

Anyway, "Andy Whoever" seems to be have been forgotten by the writers as the series progressed.

Oh.
DeBenedetto? When was it say?

I don't know which episode it's referenced, but I've come across it online.

The boss of the Paglieri family is George Paglieri. We saw him arranging a meeting between the Soprano and the Lupertazzi administration. He was played by Peter Mele.

When Uncle Junior was arrested, U.S. Attorney Gene Conigliaro was there to ask if he was interested in testifying against his nephew, Tony. He also mentioned Terese and Mangano there for the first time, but the two assumed bosses were never seen on screen.

I always was kind of pissed they never talked more about the other families at all... I also thought Andy was the guy with the glassess who visited Johnny in the Jail/Hospital about the aliquition, and he visited Tony once or twice if I remember correctly to discuss Johnnies health...

DeBenedetto was sacks son in law who insisted he call John dad

I've found on Wikipedia on the fictional gangs page mentioning the Terese, Mangano and DeBenedetto crime familys but Wikipedia isn't always reliable remember

Infinate was ginny's brother anyway but doubtfully a boss

Yes, the fictional Five Families are Lupertazzi, Paglieri, Mangano, Tarese and DeBenedetto. Case closed.

Do the other families ever appear on the show?

Obviously the Lupertazzis do. The only other one is Pagiarelli in the final episode.