Life long Bruins fan so it may be a bit slanted but I'm trying to be fair. Just based on fighters I have seen from 74 forward (So no Ferguson, Howe, Green, original 6)
1-Probert-at his best there was none better
2-Laraque-If he cared about fighting and accepted the fighter roll and embraced it he could have been number one
3-Gillies-Had wars with O'Reilly and whole time with Islanders was the toughest guy on the team.
4-McSorely-Size, reach and crazy endurance. Also legit mean.
5-Wensink-I don't remember him losing one in a Bruins uniform.
6-Grimson-Don't recall Stu losing very many either, rarely looked for fights but rarely lost
7-Kocur-When his hands were healthy with Detroit I have never seen anybody punch as hard.
8-O'Reilly-Favorite all time player besides Orr, has to be in my top ten
9-Domi-Gained respect for him as he matured, once he stopped being a sideshow he was a great fighter. Also the KO punch on Samuelson will always make him a favorite.
10-Behn Wilson-The toughest Flyer I ever saw, includes Brown, Schultz,Tocchet,Berube. Just a great fighter