>>15750060
Yep, Mike "Lips" Forelli. You can also kill the two Forelli goons that chase after you in "Dead Skunk in the Trunk" but you don't have to.
CJ kills Forellis in a couple missions, including one where he goes to Saint Marco's Bistro to slaughter a whole bunch.
Liberty City Stories makes them a common enemy by the second act of the game, and he's pretty much single-handedly responsible for wiping the family out as a significant threat. It doesn't make a whole lotta sense because up until that point they were treated as just another wing of the LC mafia but whatever, video game logic. Toni even blows up an entire neighborhood just to stick it to them.
Vance in VCS kills a bunch of hitmen to defend Phil Collins. Don't ask too many questions.
I shouldn't have to tell you about what Tommy Vercetti did to the Forellis, but needless to say he's probably killed more than anyone, second only to Toni.