Whitaker comes to mind... Dropped both Pineda and Trinidad with single body shots, yet not known as a fighter with serious power. Eh?
Whitaker punched the body well. Whitaker had a pretty good offense. He had decent hand speed, and put his combinations together really well. Whitaker lacked single shot ko power, and was comfortable going the distance. There were times I thought he could have pressed for a ko and got it(i.e. Buddy McGirt II).
Roberto Duran actually. Everyone accepts that he's a nasty body puncher but when you watch him carefully in certain fights you start to realise just how evil he could be.
This might seem out of left-field but I actually think Tua, of all people, has become a much better and underrated body puncher. Considering the paucity of heavyweights that really work the body in today's division, I'd say he could actually be one of the best around at the moment.
Kenny Norton. Norton had great body punching ability. He hurt Ali with body shots in thier first fight.
I strongly suspect some of this is due, in part, to the abolition of the 15 round distance. That the 12 round limit was ostensibly imposed for greater safety then becomes ironic, if one of the consequences of that action has been to cause a dramatic increase in punches to the head, thanks to the current artificially imposed time constraints. Bodypunching can make a much greater impact over a longer haul, obviously.
Jones in his prime. The most underrated body puncher of the last 25 years, however, is Jeff Lampkin. Unfortunately, he failed to make the most of his natural gifts, was misguided in his career, and was extremely inconsistent as a fighter. As far as pure technique goes, he is one of the best I've ever seen as a body puncher.
Tommy Hearns had a wicked left hook to the body. It was that hook that often set up his eadly right crosses.