Frazier vs. Tyson - of all the fights on you list, as funny as it sounds, this might actually be the easiest to call. I've read a few of your other answers, so I know you know boxing. Frazier did not have much, if any defense. He just walked right in, with little or no head and body movement. Against a prime Tyson, that's suicide. Tyson is the hardest puncher to put on gloves, period. Remember what happened when Joe fought Foreman and didnt move his head? This is no different.
Tyson by KO1 or 2
Cotto vs. Trinidad - this one might actually be the hardest one to pick. Cotto gets hit so much, just to get his off, you wonder how many of Tito shots he can take. He proved his chin somewhat against Mosely, who also hits a ton. Tito's chin, on the other hand, is suspect. And he's not overly fast, more of a steady moving stalker, who takes a few rounds to really find the mark. You saw when Oscar boxed his ears off the first 6 rounds of that fight. But, never forget, is his prime he mowed down whoever was put in front of him(including a sad but thorough beatdown of Sweet P, man was that ugly). It would be a test of which happened first, Cotto going down from punch accumulation, or Tito getting caught.
Tito TKO10
Hopkins vs. Monzon - Gotta go with B-Hop here. He would have frustrated Monzon with all his tactics, holding behind the head, low blows. By the end, Monzon would be so drained he wouldn't be able to hold Hopkins off
B-Hop KO12
Leonard vs. Mayweather - I hate to say this, Leonard wins here. Every bit as fast, slick and good at controlling the ring as Floyd, but with more pop. Also, the caliber of comp he beat at so many weight classes, in so many different ways, showed his amazing ability
Leonard W12 unanimous
Robinson vs. Jones Jr - Now this.... two of the top 5 greatest fighters of any size and any era....WOW. at 160, this is the fight of all history. at 168 or 175, forget it. Jones is too big, too fast, too strong, too athletic. The deciding factor? In their primes, Robinson was able to be knocked out, and was more than once, Jones wasnt even able to be hit.
Jones KO5
Pryor vs. Chavez Sr. - Both fighters known for their enormous heart.. but Pryor is, was, and always will be the best little man fighter ever.
Pryor W12 Unanimous
Duran vs. Camacho - This one is also pretty easy to call. Camacho was a good fighter. not great, but a good, solid fighter. But Duran? At this weight? Many people only remember his second and third fights with Leonard. But never forget, this was Duran's best weight, and the weight he BEAT Leonard at. Trust me, they didnt call him "little hands of stone" for nothing
Duran TKO 4
P.S. how bout this one at middleweight - B-Hop vs. Marvin Hagler?