Tyson, Jackson, Foster, Foreman, Arguello, Louis, Liston, Moore SRR, Gomez, Zarate, Spinks, EMM, Rosario, MSM.....to scratch the surface and get some obvious ones out of the way.
Hagler (still hurts guys whichever side he uses) Wladmir (good strong jab, cracking left hook, strong right hand down the middle) Shavers (Has rocked, dropped, or taken guys out with a wide variety of shots, not just the looping right) Maidana (can club away evenly with either hand)
Majority of good punchers are two handed ones. Guys who hit much harder with one hand than then other like RUddock, Cooper and Cooney were a minority and also partially because they were natural southpaws who were made to fight orthodox. Frazier is unusual in this regard. Big left hook but lacked a big right. anyway among heavies, Tyson, Foreman, Liston, Marciano, Louis, Dempsey, Wlad, Shavers, etc were all two handed ones. Majority had better rights than lefts but the lefts were nearly as powerful as the rights. Or harder in cases like Dempsey.
I always find Lewis tricky, I know he stopped Bruno with a left hook but that seemed rare for him. I do think he could hit with both hands but perhaps not as impressively as Tyson or Foreman.
Light heavies; Beterbiev, Foster, Spinks, Moore( Langford etc. Middleweights: Julian Jackson, McClellan, Hagler (although when fighting southpaw, his straight left sometimes wasn’t that strong since he was naturally right handed), SRR, GGG, and even Canelo.
Yeahhhhhhhh i was close to throwing Lewis in there but he doesn't have enough resume behind his left hand. I hope someone lists Hearns as he could really dig that hook to the body and Hagler talked his left hand up but his left is a little short of KO's. Hagler's mentioned a couple of times but i was a fair way off mentioning him personally. I find him a smidgeon below below a bonafide KO puncher especially when his left is taken into account.
A few not mentioned that had legit ko power either hand. Sandy Saddler Jose Napoles Ray Leonard John Mugabi Aaron Pryor Sonny Liston Roberto Duran (Esp lightweight /welter versions) Super feather /lightweight versions of Julio Chavez Sr.
Julian Jackson is the first fighter who always comes to my mind for "2 handed puncher" Him, along with Marciano and Foreman, are my favorites of that breed