The most significant "revenge" (though Max did nothing wrong personally) is arguably Louis vs Schmeling.
Frazier vs Ali one is the the ultimate revenge in my opinion. Especially considering how Ali tormented Frazier verbally prior to the fight.
Disagree in Lewis - Holyfield II since fight was much, much tougher for Lewis than the first one. Lewis vs Rahman - now, that was really EPIC revenge, considering the fashion of victory and their history (Rahman knocking Lennox out with a single right hand and putting him on the floor in the ESPN studio few months later).
Dude, great subject matter. Really made me think. I'll throw out: Oscar DeLaHoya v Fernando Vargas - ODLH took years of verbal abuse from Vargas at every turn. Oscar said to a commentator who asked when the fight would be made (Vargas was obviously trying to make this match in his own way), "You know something? I'm never going to fight him!" I thought that really was a unique stance on revenge. Afterall, ODLH was where the money was. And if Oscar froze Vargas out, he just denied him his greatest purse. But eventually, money does talk and they did fight and Oscar got his revenge for all the verbals over the years by knocking out Vargas after a close fight. Shane Mosley v Ricardo Mayorga - Mosley knocks out Mayorga after an altercation at the weigh-in (likely staged), where Mayorga slaps Mosley's girlfriend's behind (on youtube if anyone wants a bit of a laugh). Ingemar Johansson v Brian London - In '59 when Brian London was signed to fight Patterson for the title, the upcoming Swede made the insulting comment, "My little sister could beat London with one hand tied behind her back." Fast forward 3 or 4 years later and Ingo is facing London. Ingo is ahead on points going into the 12th and final round (Ingo's Euro title is not at stake because the EBU deemed London an unfit opponent) and gets all but KO'd by London in the final round, barely making it up in time before the bell rings. Ingo gets the decision but the ref states that he would have stopped the fight in London's favor had the bell not rung. London takes a shot at Ingo by saying something to the effect of, "Your little sister really must be something." Ingo promptly retired and although London lost, he gets a moral victory.
Lennox Lewis wiping out Rahman in the rematch was pretty sweet. Even more so because they had a brawl in the ESPN studio before the rematch, and Rahman seemed to get the upper hand in that one, too. When he was at the top, Rahman was a great smack talker. And after he knocked Lennox out, Hasim verbally and physically (ESPN scuffle) dominated Lewis every time they got together. But Lewis showed how badly he wanted Rahman again because he went to court to force an immediate rematch, and he got one. And then Lennox just "ended" Rahman with that right hand. Left him on his back with blood running out the corner of his mouth. It was very satisfying.
Apart from the already mentioned fights there is: Floyd Patterson Vs. Ingemar Johansson 2 and 3 Double revenge