I think Froch. Talk about a tough/physical fight. Froch was naturally a little bigger and he had the better chin imo. Pavlik didn't really figjt anyone of note above 160 except for BHOP at a 170 pound catchweight and he looked terrible in that fight but then again, Hopkins made a lot of good fighters look bad. I think Pavlik stays upright but loses a UD to the very physical Froch.
Froch by SD/UD or late TKO after accumulation of damage in an absolute war. Just think Froch is too big, too strong and just a tad more durable. Would likely be a FOTY candidate though. Pity Pavliks prime was so short to be honest.
Taylor boxed Froch up but got stopped. Pavlik's a better boxer than Taylor with a better chin. However, Kelly couldnt carry himself at 168lbs very well. I remember his only fight at SMW with Will Rosinsky, an NYC firefighter if i recall correctly, Pavlik couldn stop him. After the fight he basically said in the post fight interview that he didn't have it at 168.
Froch. Kessler is bigger and better than Pavlik with a similiar 1-2 dominant style with good punch power and Froch went 1-1 vs him.