He's probably had a more impressive run at LHW due to the opponents available at the weight, but his days where he was at his physical best, were obviously down at middleweight.
Well the question is most impressive.. not most peak or prime.... so I think his LHW run gives his middleweight run a good run for its money
His reign at LHW. There was really only one fight at MW that he was expected to lose in and that was against Trinidad. However at LHW he was expected to lose in several fights even as a considerable underdog and won. Pascal X 2 Tarver Pavlik Cakzaghe - I dont care what those judges say Hopkins won that fight.
Well those of us who know boxing and understand the nuances of the sport knew Hopkins was capable of what he's done for the past 5 years before he was doing it. It was clear after Trinidad that he was a top fighter at and around 160 ever. His fights with Pavlik, Tarver, and Pascal are impressive. But 21 Defences against just about anybody is impressive. The fact that he was able to beat Glen Johnson (Who everyone writes off for Hopkins, but anyone else can claim his as a great name on his resume.) Tito Trinidad (who proved himself as a good middleweight with a one sided beating of Capable William Joppy. Don't hate) and Oscar De La Hoya (who was not a proven middleweight but who most expected to do better than he did) is also exciting. I would have to say that the more impressive has been this later, 40-something year old version of him above 160 pounds, but as I said, those of us who know boxing knew he was capable of this while he was doing his damage on the middleweight division.
I'd say his Light Heavyweight run has been more impressive - including the Pavlik fight, as it was above Middleweight - but the Bernard Hopkins of around 2000 would beat today's version, in my opinion.
Middleweight for me ..Pavlik and Pascal were green compared to Hopkins so I don't put more stock in those wins over any at middle ..Regardless of his age .
This, no way this run can be more impressive than the streak at 160. On my basis his most impressive performance was against Calzaghe because I didn't expected a close fight like it was. The other opponents (including Tarver) I expected B-HOP to win with ease because their workrates fit perfectly with him (he needs those kind of opponents now), that's why he'll beat Dawson.
Hopkins 40+ run is very impressive because he's, well, an old man in the boxing world and still beating younger fighters. But there's no question he was much, much better during his 160-pound reign. Watch a fight around 1999-2001. Then watch one of his fights as a light heavyweight. You'll see a big difference.